Part of it comes down to how much I trust Roccat's drivers not to go wrong. I mean, Microsoft can't even make a mouse that moves the cursor properly, so the odds of the drivers being buggy and broken are high, and when you factor in the way my PC is set up, almost guaranteed.
The Roccat Kova is no advantage over the Kova+, as by default the Kova maps buttons 4 and 5 normally, and 6 and 7 specially instead of having duplicate left and right 4 and 5.
But lo … the driver screenshot for the Kova+ implies that it's tilt-wheel, but that's not in the spec anywhere, so now I have to wonder which of the others are.
The Kova+ advantages are the pretty lights (first mouse I've ever seen to do it right, has a nice Star Trek look to it), and honestly having more buttons doesn't hurt, because I want to have something like this on my PC, and I'm out of mouse buttons:
[ Attachment Invalid Or Does Not Exist ] 53270[/ATTACH]
The Pyro has this weird Easy-Shift nonsense that means that out of the box, buttons 4 and 5 are not Back and Forward and it relies on drivers just to get normal behaviour, so in terms of driverless there's no winning here. However, I can see their point about how Easy-Shift gives you loads more controls ...
I've never heard of Roccat before, but they win by far in terms of style (Steelseries products look really cheap and cheesy), and they've put a lot of thought and effort into the functionality, so I suspect that's where I'm headed.