I run both. A set of Candys on main commute cross bike and a set of Acids on my mountain bike winter commuter/shopper. I also have another set of Candys on my other mountain bike. The only real difference, as the basic guts are the same, is the platform of the Acids, so if for what ever reason you need to nip out in normal shoes the Acids are more comfortable.
When it comes to riding there is no real difference that I can tell, apart from weight, the Acids being heaver, I also prefer the look of the Candys particularly on my cross bike, I think they look way cooler. Both have excellent gunk clearance and my cleats fit both.
Whichever you choose, both are great and you can also get rebuild kits if you wear the peddles out, very easy to do. I love Crank Bros.
