The problem with the Alphas is they use the old Ultra SUCK footbed that really sticks to your feet. They can be difficult to get in and out of. If you take out a lot of newbies, they will hate the bindings. Make sure you get lots of lube with the Alphas.
If you're looking for a boot to fit a range of people & still provide good support, get the CWB Torq's pictured above. They have the same footbed as the Zeus/Boss/Krux and havea ton of hold down, just a little more ankle flexibility. The Alpha's will not fit the range of feet sizaes the Torq's will.
I have Mobe's from my wife's Lotus board for my "boat bindings" of course I got the L-XXL ones but everyone that has used them likes them. Hell I even rode in them once or twice just to see how they feel....I've ridden worse ;-)
I have Torq's as my back up bindings, and I have also ridden Mobes, I wear a 13 and the Torqs are much more comfortable, in fact, I like them a little bit more than my Ions, but I have torn the Torqs about 3 times in one season.