I have no problem with my widescreen whatsoever. Although it stretches the image for games that don't have widescreen resolutions, it's not really much of a problem for me. Most games (or the newer ones, at least) have some kind of hack allowing you to use a widescreen mode if it isn't natively supported. For some older games (WON Half-Life included) it's impossible for me to get a widescreen mode working, but If I don't know the game very well, then I rarely notice any stretching.
However, if you can get your widescreen to give you black bars on the sides, then that's perfect. There's no downside to that mode at all, since it wouldn't have been widescreen in the first place.
Now, contrary to what most people say about them, I don't think they improve your gaming experience much at all. What I do think they're good for is general desktop work, and viewing folders, browsing web pages, mapping, or whatever you do inside your OS's environment is way better when you have all that extra horizontal space to work with. While dual screens may be an even better option for this, that's not a reasonable option for most people, whether it's because of money or space limitations.