I like my Pearl Izumi Selects. It's a very basic shoe, and I'm sure there must be some reason that people pay more than twice as much for a shoe like the Sidi Dominator, but I couldn't tell you what that reason is.
For CX you need a shoe that will give you traction running up a muddy hill. Toe spikes can be a bonus in some conditions. A lot of people insist on a shoe with a buckle, which is more secure than Velcro and tightens down better. I've never had a problem with just Velcro straps.