Used mine as a vocal mic for a few years and it's never let me down so far. Solidly built and for the price I can't fault it. It's about 4 x cheaper than an SM58 but it definitely doesn't sound 4 x worse.
The Behringer XM8500 is not a microphone I would pick if money was no option but that doesn't mean it's bad. I use it for on-the-go recording or when I can't be bothered heading to the studio. With a price tag of less than £20 (~$30) you'd except terrible quality, but to be honest, this microphone isn't terrible. It has a decent frequency range and is very durable, like a slightly worse Shure SM58. Definitely worth getting one if you want a good vocal mic but are a bit strapped for cash.