It is also built on off the MK3 platform (308) so it will be big and heavy. Might as well get 3 AK's and SBR on for that price.
I actually handled one the other day and was really impressed that it wasn't big and heavy feeling like the MK3s are. What they did here was take a MK3 and shorten it, then turned down the diameter bolt's rear section, and milled the breech face to accept the x39 case head. By shortening the action, they removed weight and moved the center of gravity significantly toward the rear where the weight is easier to manage, giving it a very balanced feel that is nothing like the MK3. CMMG also appears to have used a narrower barrel than what's on the MK3 and also kept the front end light by using a key-mod free float rail. All in all, it only feels slightly heavier than a standard AR, much lighter than an MK3, and very well balanced overall.
I am very interested to see where they take this new model. If they make a few adaptations I may actually consider picking one up instead of getting a 300blk just to save money on ammo.
My issues with it arises from the combination of two features: (1) no bolt hold-open; and (2) the t-style charging handle. Because the bolt is not held open after the last round, you either have to keep track of your rounds and make sure you change mags with a round in the chamber, or constantly to use the t-style charging handle every time you do a reload, rather than charging it via the bolt release. This isn't a problem with standard AR's because you typically charge it using the handle only infrequently, rather than charging them by inserting a fresh mag and pressing the bolt release. The Mutant's t-handle uses a very small latch which, when combined with the heavier buffer spring, makes the vestigial little latch marginal at best for getting a grip to rapidly charge the firearm. Since it uses a shortened MK3 charging handle, there aren't any BCM Gunfighter style charging handles available for the firearm YET, which would make constantly operating the action manually much, much, easier. If someone comes out with an embiggened charging handle for the Mutant, then I will more seriously consider it. Also, if CMMG can figure out a way to put a FAL-style side-charging handle on the Mutant, like New Frontier's side-charging AR upper, I think that would be the most significant upgrade that could be hoped for with this firearm.
There is my $.02, take it for as much as you paid for it.