I'm of two minds, really. I voted no, but sometimes I have fun on Versus. It just seems there are a lot of downsides. You'll find jerks who don't play the way you would think is fair, or you'll just find flat-out jerks. :\ Also, people seem to have issues with lag. I have not had this issue, but I don't play Versus on a regular basis.
I bought Versus because I'm sort of obsessed with completing my games. I think it'll be most worth the money if you have a lot of online friends who you can trust.