I've ordered the basic MSI 650i SLi Motherboard - will see how it fairs. To be honest, the primary concerns were 1) 2xIDE ports as I still have 3x IDE devices and 2) cost.
I needed something cheap but didnt really want Crossfire and the Asus 650i didn't have great reviews due to vdroop and just general board layout. If I am honest, I would forget the 650i and get the 680i if I had a load of cash sat about, but I don't so will test the MSI and let you know if you like.
Still - if you have £150 to spend (or prob more like $300 at the moment) then I would prob get a Asus P5N32-E Sli 680i or similar. But for me - I thought I'd use the money on the gfx card instead.