I got a new pair of X-Alps for the 2014 season. I never did find the X-Projects in a store where I could try them on so I didn't make a decision to choose one over the other.
As you probably know, the X-Projects are a little lighter weight with the trade-off that the sole is stiffer, which means better power transfer while pedalling the bike but not as comfortable if you're travelling on foot for a long time.
Harps tried the first version of the X-Projects and his initial review wasn't positive - tight fitting, blisters, etc. I'm not sure whether he learned to love them eventually.
My rationale for not looking harder for the X-Projects was that I already have bike shoes that are lightweight with good power transfer; those are the ones I wear when I'm mostly planning to stay on my bike. When I wear the X-Alps, it is because I expect to spend a lot of time on foot, e.g. I've usually done Storm The Trent, ESAR and Storm the 'Scarpment entirely in bike shoes. I decided to go with the shoe that is more comfortable on foot even though it's not the best "racing" shoe.