Yeah, my friend has a Gyration combo. I really like it too. I was thinking of picking one up, but I wanted a single keyboard/mouse unit. Just want it a single package. So far, I haven't seen or used one that has met my expectations.
I like the xGene because it's got a nice looking marble optical mouse. So far, the reviews say it's pretty accurate. I just ordered on from the sensuz store. i should be getting it next week. I'll post an update once I get it.