Anything where you can lock the strings at the head, otherwise every time you bend the strings you'll lose your tuning. More valid at the cheaper end of the range, and something to watch for.

Overheard a conversation at the local guitar shop - someone was buying a second-hand guitar and asked whether there was any real difference between the "genuine article" axes and the cheaper imitations. Salesman said, "as long as you get a decent guitar and you like the sound, there's no difference, so there's no need to spend more." Ain't it nice to find an honest salesman who likes the music more than his profits... :-)

Grab.