Yeah, I find DXM fairly useful, but remember not to use with codeine, and with some drugs (oxy/hydrocodone), it may make it take a bit longer to kick in (in my experience), and with others (dihydrocodeine), it makes it kick in quicker.
Makes it nice to mix hydrocodone and dihydrocodeine, since they kick in pretty close to each other.
Of course, your results may vary. It also reduces itching and nausea, although I sort of like the itching and nausea (call me strange, but the itching and nausea just go hand in hand with the experience, they sorta of... I dunno, of course, I've never thrown up or scratched myself raw, so this might be a blessing for some people).