I think it is going to be hard to compare them especially with the price difference of a 2008 Curve SL to a 2008 Mini at almost half the cost. Right off the bat the Curve has components like Kinetix, Big Apple, Bontrager, Avid. The Mini is just plain cool and is looking for an upgrade where the Curve is pretty much already upgraded. I have to admit I like the curves of the Curve and that is what is so appealing about it.
I bought the Mini first and then the Curve came up for sale, I wanted to try them both. Just got back after riding the Curve, the bike feels solid but 5 gears and a 13t sprocket too much pedaling. The big Apples make a comfortable ride.