I've looked at them before. The ones that I've handled seemed like a solid AK. I'll give you a list of pros/cons IMO strictly:
Pros:
Price-Where else would you find a milled AK for $550?
Made in America-some average joe like me put this thing together.
Looks-looks great IMO, and there are a few different wood or plastic stock options
Cons:
The looks of the rifle are great, but look on the receiver for a giant ass billboard-turns me off
Made in America-foreign parts are a good thing on an AK. Commie CHF barrels are important to me, may not be to you
Misleading marketing-these are not 100% USA made like CAI claims
Neutered gas block, no provision for cleaning rod