Are there any noticeable differences between the Steam and GOG versions of the game?

This version doesn't have a problem with multi-core processors while the Steam version last I had checked does.

Also UniWS works on the Steam version (kinda sorta) while it hasn't been updated for the GOG version yet.

They seem to have fixed the problem with multi-core CPUs.

The Steam version doesn't have the opening video, does the GOG version include this?
Also, what about the Yavin Station DLC, is that included? I don't remember if the Steam version has the Yavin Station. Does the GOG version support mods in any way?

There is no DLC for this game. It was released way before DLC appeared. To answer the topic, my steam version works only with cinematics disabled (and believe me, I've tried), while the GoG version works perfectly without touching anything. Worth the buy, definitly !

There is DLC for this game, Yavin Station DLC, I bought it for the XBOX version way way back. It was a space station at Yavin that had a store in it with special equipment only available at that station. I just did some checking, and the PC version includes it. So no DLC for the PC version, but DLC for the original XBOX version.

The PC version always had the Yavin station. Only the Xbox had it as DLC.

I use the Steam version with Windows 8.1 64-bit and after weeks of searching for solutions and fiddling with the config files I got it to work perfectly with all the videos playing and upscaled to fit the screen (it doesn't even look bad). I wish I had saved all the different sites where I got advice from on how to make everything work but unfortunately I didnt. What I am saying is that if you try hard enough, the Steam version will work. I would hope the GOG version works right out of the box as this is a great good old game that everyone should be able to enjoy.

For those of you who have problems and want to try finding a solution I have to say my version only works in a very specific environment. It doesn't work with my laptops native resoluion (1366x768), so I have to connect it to the tv and play with a higher resolution ironically (1920x1080).

Oh, and the steam version DOES have the intro movie (with "a long time ago in a galaxy far, far away and the standard starwars crawling text before the movie) unless it's a different movie I am not aware of.

Yes there is another intro video that normally plays right after the Lucas Arts and Bioware logo, I cannot post a link here for some reason, but it is on YouTube listed as Star Wars: Knights of the Old Republic - Intro (HD), posted by a person called Ravanofdarkness. But I have never seen it play in the Steam version, but it was there in the old XBOX version.

You need certain amount of reputation (7 or something) to post links. It's to prevent spam posts. You get one rep per day you post something so you get link posting privlidges soon enough by participating in various discussions in the forum.

Also that vid is a promo and was not in the pc game... simple enought to add it but no.

Yeesh, that video is spoilerific and I'm quite happy that it wasn't at the start of the game.

I have waited this game on Gog since a long long time ! So happy to have this, and in French, cool !

I have done KOTOR 2 in the past on my xbox, I hope to have it on GOG, but I remember that the second Kotor wasn't good as the first.

Well the first one has an ending so that makes it better in my mind but the second one adds some extra feats and armour which makes up for being un-finished in the mind of Bioware.

Kotor 2 was quite good but it was rushed and had most of its rather interesting and even the ending content removed.
But for that we have the KotoR 2 Restored Content Mod:
http://www.moddb.com/mods/the-sith-lords-restored-content-mod-tslrcm

More insight of what happened to that game:
[url=http://starwars.wikia.com/wiki/Cut_content_from_Star_Wars:_Knights_of_the_Old_Republic_II:_The_Sith_Lords]http://starwars.wikia.com/wiki/Cut_content_from_Star_Wars:_Knights_of_the_Old_Republic_II:_The_Sith_Lords[/url]

I hope, when KotoR 2 finally arrives, that this mod will be linked as it not only fixes some bugs and removes huge plotholes(G0-T0s and HKs) but also gives the game an alternate ending.

Check it out when it arrives here!