Well, I just got my Incase sleeve today, and as promised will post my first thoughts...
It's a nice sleeve, there's three extra pockets, one on each side and one inside the sleeve. The inside of the sleeve is very soft and smooth, makes for easy sliding into the sleeve. The handles are a boon, makes it easy to hold and carry around. It's minimalist looks fits my black MacBook. And there's some cushion between the laptop and the zippers when closed, so your laptop won't be scratched.
But if you want a sleeve that's very smug, this might disappoint. The sides are smug, but the top has a little room, similar to the neoprene sleeves.
Bottom line is that this is a very good sleeve. There probably are better ones out there, but there definitely are much worse ones as well. I'm satisified with my purchase.