I've also got large hands (XXL gloves here, too, at least for the width). It took me a few weeks to get used to the key layout, but the keyboard doesn't feel at all cramped now. My only size-related complaint is that if you've also got wide shoulders, you may wish that you could adjust the angles of the keywell and thumb areas.
Despite that, this keyboard has been working out much better for me than the old Goldtouch split keyboard that I used before I got the Kinesis Advantage. The Advantage doesn't have the adjustability, but the mechanical keys, contoured wells, and thumb keys seem to more than compensate.
The function keys are as bad as hoggy says. I go out of my way to avoid using them. The bracket keys are in weird spots too if you're a programmer. There are remapping suggestions in some of the other Kinesis-related threads.
Kinesis offers a 60 day money back guarantee on keyboards purchased from them. They told me when I visited that their return rate is very low. I don't remember the exact number now, but it was in the low single digits.