I fully support the notion of keeping GOG Downloader alive and I regularly do my part to report dead links to GOG and encourage them to fix them, and I will continue to do so. Having said that, ever since Galaxy client came out I have been using it as my primary means of downloading all of my game installers and extras for backup purposes. I have used it for direct installation of games from time to time also, but I mostly use it to download backups whenever any of my games show up in the "What did just update?" thread.
In the last 2 years of using Galaxy client, like everyone I have encountered various bugs in it over time. I have reported the majority of them to GOG either via their mantis bug tracker at
http://mantis.gog.com (as I encourage everyone to do), or mentioned them in the GOG GALAXY BETA thread or the "What did just break?" thread or directly to GOG support.
As my primary downloading tool in all of this time, I have had relatively few problems with Galaxy client both in terms of performance, reliability, and file availability. I might have experienced slow downloads once or twice in passing over that time, but it has never been something consistent to be a big problem for me. The majority of the time I am able to saturate my 30Mbit Internet connection to 3.5MB/s download speeds consistently via Galaxy, which is the same speed I max out at in Steam or any other software. It is important too to realize however that one person's experience good or bad does not dictate how everyone else's experience should or will be because we do not all connect to the exact same physical computer when we download things, but rather GOG uses a CDN to distribute files and there are potentially many servers out there from region to region. Problems that occur on their CDN will generally be limited only to people who live within the region served by that CDN while the rest of the world goes on experiencing no problems at all.
It seems from observations over time that the quality of service provided by some of the CDN providers out there may vary greatly from one country to another around the world, and as such people living in certain countries tend to experience more outages, performance problems and other issues compared to the average. Naturally if someone continuously has these kind of bad experiences they may become bitter with the software and with GOG and think that the experience that they have is the same experience that everyone has.
That is not the case however.
On very rare occasions I have went to download an updated game via Galaxy and get a server failure error stating that the files are not there or something. Yes, that frustrates me. I contact Judas directly about such missing files and fire off a polite friendly communication to him and he usually fixes it in anywhere from minutes to a day or so depending on the timing of everything, otherwise I pass it through support and they get the job done also but it may take a bit of back and forth until things happen. On the surface this might sound like it is a problem with their Galaxy setup and a reason to not use it, but the truth of the matter is that I've had the exact same problem with GOG Downloader and also with the direct download links on the GOG website and I report all of those to them too. Galaxy is no worse and no better in this particular problem than any of the other download methods at least from my standpoint here in Canada using whatever CDN they use here. Whenever I've had problems with any of these methods I've reported them publicly also either in the "what did break" thread, the GALAXY thread, or the updates thread, so there is a consistent public track record of that.
At the end of the day though, while Galaxy isn't perfect and it lacks a number of features and frills that will no doubt come later eventually - it is pretty good overall at what it does do right now even if one has had a problem with it from time to time. It is beta and so it will have more problems than a released stable piece of software, but it has improved dramatically over time and continues to get better.
While I would like to see the Downloader app kept around as long as possible along with the web back end to support it, and I'd like to see them maintain the file links properly for that to all work, I also think people are often incredibly harsh on Galaxy and make it out to be completely unusable crap when it is actually quite usable for most people out there.
The truth of the matter is that no matter how many votes "bring back Downloader" gets on the wishlist, GOG is simply not going to do that really. They're moving on and everyone else should do so also, and the best possible way that people can do that is if they are using an operating system that Galaxy is compatible with (Windows 7 and newer, or whatever Mac versions are supported), and if their computer is new enough to have the resources to run Galaxy without any major problems - to install Galaxy and try to use it and more importantly to POLITELY report bugs to GOG via
http://mantis.gog.com when there are problems. Only by receiving bug reports are they likely to be able to resolve issues sooner than later, but if nobody reports them then we get a client that is whatever they happen to find during internal testing on their own, which is not going to reflect how everyone else uses it out in the wild. That is why it is a public beta, so that people (us) can test it and report back bugs/problems we experience - preferably without the use of profanity and grumbling. Professional bug reports with maximum data on reproducing the problems goes a lot further to getting a solid usable product than "Galaxy sucks, bring back the old stuff you are getting rid of" really.
For those who have computers that are too low on memory or too slow, or running an unsupported OS, that is unfortunate and you'll have to either use the unofficial XP/Vista patch floating around in the forums for Galaxy if possible, or stick with the unsupported Downloader or web browser methods or gogrepo.py et al for now.
However, there is another good reason for people to test Galaxy and report back professional bug reports to GOG as well. They're committed to the client and the API and it isn't going to go away, but it is going to get better over time. Eventually we will also have other 3rd party download clients that themselves use the Galaxy APIs to download games but are perhaps lightweight download-only clients. Eventually, most people who do not want GOG's fully fledged official Galaxy client will probably move on to one of the 3rd party clients that use the Galaxy API instead. The more people who test out the official Galaxy client now and report bugs so GOG can fix them, the sooner the entire product and API becomes more stable and the sooner that 3rd party clients will become available that are a viable alternative.
Personally I would love to see such a 3rd party client exist that makes GOG Downloader not only obsolete but completely unnecessary, and which doesn't require anyone to have the Galaxy client installed if they don't want its full functionality. Someone has already published some documentation in the forums about what they've reverse engineered about the Galaxy API, and that effort will likely continue and eventually something usable for everyone will result.
The way I see the future here for all of us is a positive one whether someone uses GOG's official client or not. The only bad future there will be is for the people who cling with two fists onto the old GOG Downloader though because GOG has made it quite clear it is going to eventually go away, and y'all are going to be super pissed the day that happens unless you've found alternatives that are as good or better - which is all that I'm encouraging everyone to do at the moment.
So do continue using GOG Downloader in order to keep it alive as long as possible (as I've suggested in another thread not long ago) and vote for it by actually using it and keeping it running 24/7 so they see connections on their servers, but please also join in the beta testing of Galaxy client so that we can all have something superior in the future - but hopefully sooner than later. But voting to keep something alive that is already 6 feet under, is just beating a dead horse - it isn't going to happen. Please help GOG perfect the new API so we all have something decent and can stick a gravestone above the old stuff for good.