Update-I've had this for about a month or two and a plastic clip on it broke!  The pack wasn't overly full and didn't have anything wildly heavy.  I would have done better to get a cheap backpack at Wal-Mart!

Pros-lightweight, venting keeps it from getting too hot.
Cons-not a very good shape for carrying stuff.  My old Petzl bug backpack fits a lot more and is more durable.