I've been using CAV-15 lowers since about 2003; it's amazing how much dead weight you can lose, without compromising reliability or busting the budget, simply by going with a GWACS/Cav Arms lower, and carefully selecting other reasonably priced, "off the shelf" components. I recently assembled a CAV-15 carbine that came in at 4.75 pounds (5.25 lbs with red dot sight, empty 20-rd mag, & sling). Holding something like that in your hands, you realize why our fathers & grandfathers loved the M1 carbine!
;^)
I read on their Facebook page that they are working on having more MK II, as well as newer versions available this year. I hope so, as I am definitely interested in trying one.