I'm not on a Vex team, but I did get a couple of minutes of quality time with one at Palmetto.
Knowing that they're $300 (and the Robovation kit that rookies get goes for $595 on
IFI's website, or just the controller itself is $250 without a radio), I'd say they're worth the money. The materials look pretty much like Robovation materials, but the controller and radio look and feel a bit more finished than the Robovation's setup. (The radio felt good in my hands--but then again, I have big hands. I can't use anything but the XBox Duke controller. So you might want to watch out if you've got really small students.) Programming remains a mystery, although I did notice that they're using non-standard ports on the back of the controller itself, which makes me think there's some proprietary something-or-other going on within. (Little do they know that we have folks like Kevin Watson in our camp. Fwahaahaa.
)
If I had the money right now, I would buy one. (But that's another story.)