I purchased this gun about a week ago, test shot it for a while, and was a tad dissapointed. I own a CA M249 MKII as well as this and you could easily tell the build-quality internally was better than the A&K just from hearing them both fire. However, I took the A&K's gearbox apart to give it some maintenance, my final synopsis can be found below.
Externally, the build is quite solid. I would put it on-par with my CA in terms of durability.
The bipod performs great, much better than my CA.
The carry handle is very sturdy.
The box mag, when clamped into the gun, remains very solid on the gun.
The railed feed tray is good for mounting optics.
The folding stock gives it the ability to become a very short weapon for more mobility.
Had metal bushings and spring guide which are always great to see.
Hop-up is great and very easy to adjust. I got mine zero'd in less than 5 minutes.
Pretty accurate for it's size. I can hit a man-sized target 7/10 times at 200ft. with .20's.
The stock shimming of this gun is actually pretty good.
Its weight is actually quite bearable, although most of the smaller players are going to want to avoid this gun because of its weight and size.
Shoots about 360FPS which means it is legal at most outdoor fields but still packs a punch.
The lower handguard (that holds the battery) has a tendency to pop-off once in a while due to the way it's attached to the rest of the gun.
The feeding system and hop-up unit are a bit hard to line up correctly (this is a problem with all M249's regardless of brand though).
The springs for the buttons that keep the feed tray locked down are a bit weak.
The bipod of the gun cannot be extended to it's full length (as it has multiple positions) if the box mag is attached (once again, this is a problem with all M249's).
The para stock is very uncomfortable to shoulder when it is retracted all the way.
The stock grease that is in the gearbox is absolute garbage and should be cleaned immediately.
The micro-switch on this gun is also junk and should be replaced (another problem with all M249's).
The box mag's side cover tends to pop off for no reason, spilling out all your BB's. The only way I've found to fix this is to put tape or rubber bands around the box mag to keep the door attached.
The auto-winding feature of the box mag is absolute garbage and rarely ever works.
Rating: [3 of 5 Stars!]