jefequeso: How so? I don't see a difference between the two of them.
The Fallout engine was a lot "slower". You didn't just stumble through the maps like a drunken, pig legged dwarf. But carefully walked through them. Combat was turnbased and allowed for a lot more "combat chatter".
Also much less voice work. More to read. And the little TV screen often offered very good descriptions that helped with immersion. And when they did voice work on a char it was fully done and glorious. Also, the voice actors where _a lot_ better in F 1 + 2 than in most IE games (especially BG)
Generally, a lot more to read. The pip-boy and the several computers added a nice touch. Personally I also like the special "dialogue interface".
The only IE game I like is PS:T. And that was because it pretty much took you from "one page to the next". And for once, in the weirdness of Sigil, the graphics did work.