erm.. you could download it and try it out for yourself.. mods for the Quake engine have been around for ages, as well as many other games.. many incorporate sounds from various places/movies/other games etc.. and this has to be the first time i've seen this type of question posed about it lol.. mods are great, they make owning a pc, and playing pc games all the more interesting. if you have some free time, i suggest you pick up a copy of Thief 2 (yes TWO:)), and grab some of the user made mods for that... or a copy of half life, and try the They Hunger mods. fwiw i downloaded this doom 3 mod, as well as the Duct Tap mod (to put the flashlight on various weapons) and their both quite well done.

Actually Counterstrike was the only mod I really accepted as something "legit". I don't want to use "some" new sounds in DOOM. If I use new sounds, they should be as legit as the original sounds are. It's no problem to mix some sounds from other games, but that should then be marked as that. Personally I don't like those new sounds better than the original ones, especially the pistol, that everybody seems to dislike. The new sound is too heavy for that weak weapon. Who does seriously use it later in the game? And that is just represented by the sound. I think the original sounds fit perfectly.

i've already beat the game 2x, and almost finished a 3rd... my next go will be nightmare level. once a games played a couple times.. mods are welcome additions, that can enhance or at least refresh some parts of the game that might be kinda drab.. lets face it no matter how cool a game is.. after about the 5th time through, you can probably make a nice long list of "quirks" in a game that should have or could have been different. and what do you mean by "legit" if a company releases an SDK to allow people to make mods such as these or any others, then you can classify those as "legit" sounds.. psh their nothing to make most are all the same type of format, some are ogg, some are wav, some are mp3's... all 3 of which can be made on your pc and changed to fit your needs, you dont like a gun sound in this pack, you can go find one you do like, and drop it in (just rename it to the exact name in the pk4 file) and theres your "mod" as legit as you want it to be:) its always your choice to use or not use mods, but to dismiss them so easily, robs you of a "freebie" for pc games, not to mention alot of people spend hours doing those mods to bring some added fun to the game, it'd be a shame to let all that hard work go for nothing. any mod makers reading this.. keep it up.. some of us appreciate you:) cheers