I don't have to worry about remembering the solutions to the puzzles. I don't think I ever solved any the first time around.
I'm much better at puzzles than I used to be, though, so I figure I've got a better shot.
The myst puzzles were always solvable because there were hints in the books in the library. The two hardest ones for me were getting into Channelwood Age, because I had a hell of a time finding the spot to click on to get to the big tree on the island, and a similar problem finding a specific location among the huts in that age. Navigating in the point-and-click environment was sometimes very difficult because you didn't have an indication of how far you'd rotated. Sometimes it was just a little bit, sometimes it was a full 180.
This is one of the reasons I really think RealMyst is the definitive version of the game. It takes the artificial difficulty out of the game but leaves the real puzzles intact.

Well, I mapped out every bit of the undeground train maze to get through it. I think I still have the map lying around somewhere....
I will have to disagree that Realmyst is any kind of definitive though, the graphical quality is comparably laughable, I feel the realtime navigation adds nothingin terms of easing navigation while breaking the immersion provided by the superior imagery and sound of the original. Myst feels like a real place in my mind even now. Realmyst is like a bad tech demo, exposing what shouldn't be exposed and easing what shouldn't be eased.

Different strokes, I guess. Side-by-side I think the graphics in realMyst are a step up. They're more detailed than the originals for sure.
As for the train...I made a map my first time as well, until I finally figured out the purpose of the sound effects.

Not really, I tried only the demo mind, but all the little things like the dramatic shadows and the high contrast sunlight just felt empty and then it started to rain that shitty unrealistic rain all the time for no reason. The "dark" tunnel had so much light in it it wasn't even hidden, let alone hard to find the compass. And the impressive animations of the little things with the well rendered materials in the rooms became wierd spasms with shitty low resolution textures and aliasing in swathes to boot.
What a joke.

For me, RealMYST provides an interesting case study in what we accept as "real," especially when we're not talking about CryEngine2 level visuals. It's similar to the comparison between stop-motion and CG animation. The puppets provide a tactile physicality that computer animation, until recently (and still fleetingly), struggles with. But stop-motion, in turn, struggles with the fluid and purposeful motion of real life. Which is more important to the illusion?
In RealMYST, the player can move smoothly around the world as they would if actually walking in the those locations. But the environment is obviously and patently virtual. As with all game engines of the time (and many of this time), objects all appear flat, hollow, and weightless. They have no real texture - only color, and are lit only by the timid, lifeless highlights of Gouraud shading technology. Classic Myst, by comparison, has only slightly less polygonal and texture detail, while providing a world of difference in the lighting. Ray-tracing provides crisp, vivid light from burning whites to rich blacks, bump maps create real surface texture, every object casts and receives shadows, and metal and wood and marble can all be distinguished simply by the way they react to and disperse light. Above it all, the hazy glow of Myst's sky is done as well as the effect can be done. BUT... it doesn't move. In short, RealMYST puts you in there, IN the world, albeit a world that obviously exists inside a computer. Classic Myst creates a world that much more plausibly exists in reality... somewhere... even if all we can see of it is a long series of snapshots. It must be left to each individual player to decide which compromise they prefer.
Personally, I like both versions, but would call the original "definitive" because it came first and because the performances are better. I thought the new video and voice-over recordings in RealMYST were pretty bad.
EDIT: Btw, on my first playthrough I got to Mechanical before Selenitic, and thus learned the sound cues used for the maze well ahead of time and had no problem with it. It's been kind of amusing to learn, many years later, how infamous that part has become. :) I do agree about the hotspot outside the boiler cabin, though - that was definitely my biggest frustration.

There are two DVD versions of Riven, one released shortly after the CD version in 1998 or so and one as part of the 10th anniversary edition of Myst a couple of years back. The main selling points of the original DVD version were better graphics in the cut scenes (the QT movies) and improved sound. And a "making of" video was included too. The 10th anniversary DVD comes and works with a newer version of QT but should otherwise be the same. I have the CD version and both DVD versions of Riven and the differences in quality of the cut scenes betwwen CD and DVD are definitely quite noticeable, if not substantial. There are no differences in graphics apart from the movies.
Based on the size of the download, the GOG version is most likely the CD version.

Honestly, I don't recall a case where GoG actually opted for the DVD version. I wish they would either include both or use the superior one.

Well they must have gotten the game directly from Cyan, no?

I have the DVD-ROM "10th anniversary" edition which has the Ubi Soft logo in the intro instead of Red Orb. I can confirm that the videos in the DVD version are slightly better, and furthermore GOG does not have it. GOG sells the inferior version!

I'm not surprised that the GoG release is not the DVD version, which is the reason I'm not going to buy it because I have the DVD one on disc.

I'm sorry, but that is bullshit. I have the CD version and the screenshot you present as being from the CD is nowhere near as good as it looked. I'll accept there might be an improvement in the DVD version, but it's certainly not as drastic as you make it out to be considering that shot is far worse than the CD version ever looked.

Now if the only difference is the quality of the videos, would it be easy to replace the ones in the GoG version with the videos from the DVD version?

Are you able to at least include improved media files as a bonus download for titles like this so users can improve the games on their own accord, with no guarantee?

I never owned the original DVD version, but I own the 10th Anniversary edition and I heard that all it was was the 5 cds put onto one disc. I can't confirm this or not, but this is the version that Steam has. Unfortunately, I purchased the Cyan Complete Pack on Steam because It contained Myst Masterpiece Edition, realMyst, Riven, Uru Complete Chronicles, and The Manhole Masterpiece Edition for $20, which is $14 cheaper than here on Gog.com. (It also included two more early Cyan children's games which I'm not too interested in other than as a piece of video games history [the precursor to Myst] but it still made the deal better). If Gog was to include the DVD version, then it might be more incentive to buy the game here, since GOG's policies and customer services are 100 times greater than Steam's. That's why when GOG (hopefully) releases Myst V I'll buy it.

Not complaining or anything (I've never been more happy with a service than GOG), I just thought I'd add that there's a market for the DVD version!