For my Mac at home, I've got my Kinesis hooked up through a now-discontinued Belkin adapter (they've got a replacement that looks smaller and nicer than my old one). It largely works without complaint. Once every month or two, my keyboard won't be working and I'll have to power-cycle the Belkin adapter to make it work. I've experienced similar needs for power cycling with the internal USB hub in my Apple monitor, so it's hard to say what, exactly, is the cause of the problem.

In practice, the Belkin adapter does all the right things. I still keep my original Mac keyboard plugged in for the odd times that I need the Option key, the CD Eject key, or the volume buttons, none of which are on a standard PS/2 keyboard.