If you like Colson, but don't want to bother with separate hub manufacturing or purchase, check out NPC wheels which have very similar characteristics and have hub included:
http://www.robotmarketplace.com/prod...lrin_hubs.html
1712 used NPC wheels in its drivetrain in 2006, 2007, 2008, and 2010. During those years the wheels performed very well on all kinds of surfaces, including those similar to what is being used this year, and in all kinds of configurations (4-wheel, 6-wheel, wide-body, long-body).
As pointed out you will expend a little weight here, but when I was in a decision-making position, I always thought it was weight well spent for a wheel that will last, get around, help you score, and stand up to playing aggressive defense when/if a game or strategy calls for it. I'm also sure there are plenty of places you could take some mass out of the wheels if you wanted/needed to as well.
And while we never grooved the NPC wheels to improve traction on a competition robot, I'm well aware of the success Brando and others have had with this technique and did like what I saw with some off-season lab testing several years back.