You've got it figured out completely. They badge the DRM-free ones, and the only real difference is that the site only gives you something like 3 activations on your games automatically. You have as many as you want, but after 3 or so you have to email them for more.
At least I've heard that. I have yet to install and uninstall a single game three times. Also, they have the fastest DD servers, which is a huuuuge plus compared to services like GamersGate.

Impulse gave me a good 5mbps a few times, and I'm using middle priced charter internet. I think it was down hours before school and work got out around 2pm. That's fastest I remember getting from any DD I use, Steam gives me 2mbps at most.

D2D had HORRIBLE speeds for Europe till few months ago. Recently they seem to have mostly fix them.
I only have a 24mbt connect with about 14 real speed. I get that from all the stores depending on server load and time.
For example Gamersgate's better times are in the early morning, Steam in the middle of the night, Gog evenings, D2D late night.

The original's been DRM free for awhile. ArmA 2 dropped the SecuROM with the most recent patch.

Yes, Impulse is supposed to be fastest.

Which service is fastest will depend on many factors. Such as the location of their servers in relation to you, time of day, how many other people are using the same server's bandwidth, your available bandwidth and so on. As such, it is very likely that different services will be faster for different people.
So ultimately, it's a bit pointless to claim any one service as being the definitive fastest service -- as that service may very well be the slowest for someone else.

then email their (d2d) service, they helped me once when i couldnt buy a game

Deus Ex Collectıon is $5.00 on Steam, each games are $2.50.

Never played Deus Ex Invisible War but have repeatedly seen people say it's a huge disappointment -- any thoughts?

Good on its own, terrible compared to first game seems to be the consensus. Similar to BioShock and System Shock?

This means I can finally get Deus Ex for an really cheap price.
(I already got 2 for the xbox, because it was like £2, but haven't played it, as I wanted to go through the first one!).
Thanks for the Tip!
(But now this means I can't get anything else for a while. Meat Loaf sapped the rest of mah cash! (Hang Cool Teddy Bear was an instabuy! Couldn't resist that deluxe edition with the live tracks))

I played IW before the original and I loved it. If you've played the original Deus Ex, just pretend that it's not a sequel and you should enjoy it.
Edit: I enjoyed IW enough that it made me seek out the original and play it.

Bioshock is a lot better than Deus Ex: IW though, isn't it?
Also Bioshock is a "Spiritual successor". Sort of. Not a direct sequel.
Edit 2: This was in reply to chautemoc's post. Seems edit after reply breaks something or other....

The SupCom gold pack on Impulse is great because they do the patches for you without the GPG service, which I didn't get to work with my original boxed copy of SupCom. Gold pack also has the expansion, but it's $30: http://www.impulsedriven.com/products/ESD-IMP-W115
You could get both on Amazon.com for about $15 total plus shipping for boxed versions, count shipping they might end up same cost and on top of that you have to patch it manually or with GPG and that can make the game a chore before you play. Also the gold pack version on CD's is $20 even on sale right now on amazon. Depends on you, Impulse gave me a sale once and I got it at $20 for the gold pack but that was a few years ago.
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=supreme+commander&x=0&y=0
OR: Best option of all, get the Spring engine and lobby. It's an engine used to run 'mods' which are basically whole games similar to Total Annihilation, different ones have different units but in general play similar, with WW2 to Sci-Fi games. Best of all....IT'S FREE!!!!!!!!! I'm currently playing the 7.12 version of Balanced Annihilation and XTA 9.6, my two favorite mods and both are based off Total Annihilation.
http://springrts.com/