I just received my last order of three of these - I'm very pleased with them.
Especially since you can charge them via USB connection *WHILE* you use them.
It still uses the cordless receiver even though it's corded via USB.
I can't see any reason why it wouldn't work with Vista - there are no drivers to install.
The mini-CD that comes with it only has a PDF user manual on it, and there isn't a mention of Vista. (I would imagine the product came out before Vista.)
I've read some of the reviews about the rechargeable batteries not lasting very long - that might be the case, but they are standard AAA-sized batteries, so I'm sure you could replace them with regular/alkaline/lithium/other rechargeables if you so desired.
I really like the fact that the receiver stores in the underside (similar to the MS wireless notebook mouse), but the receiver is not as big as the Microsoft one.
Decent cost, works well, it's a keeper for me.
Now if I can just catch them up again for sale to get a few others for spares/gifts/etc.