One thing I don't understand entirely, is does something like this still count as SBR since it can be removed and attached easily?
Yes, if you put a stock on it. Even if you can easily remove the stock afterwards, putting it on your particular gun (because it has a barrel that is less than 16") would make it an SBR. If you do not fill out the paper work and get a tax stamp first that makes it an unregistered SBR and is a felony.
Was also wondering about the benefits of say a krink break or one of those multi-piece brake kits vs something like;
The muzzle device you have linked to there is a flash hider and works very differently than a brake. Also, not trying to be a jerk, just an FYI, the proper terms is a muzzle brake not a break. Brakes and compensators work to reduce felt recoil and muzzle rise. To me their main advantage on a gun like yours is to reduce muzzle rise and to reduce the split time between aimed shots. The down side of a brake is that the increase, flash, blast, and noise. This is particularly true from the perspective of some one to the sides of the gun. A flash hider on the other hand does just what its name says, it reduces the muzzle flash and signature. I'm not sure if you've fired yours at night, but my experience with short AKs is they have a pretty serious flash that is blinding to the shooter if fired in really low light.
The 4 piece Bulgarian brakes were largely used to increase back pressure and make a very short gun more reliable. I really doubt you will see any benefit in that regard. They also help to direct blast down range and away from the shooter and those around them. They, as far as I can tell, are not great at recoil/muzzle rise mitigation. Nor are they that great at hiding flash. In fact they often shoot out impressive flames. There is a reason the Noveske KX3 which is HEAVILY inspired by the Bulgarian 4 piece brakes is called "the flaming pig."
The bulgy brakes just look awesome. However, they are both long and heavy. They add inches and a lot of ounces. All that weight is put in a pretty bad place too, right at the end of the muzzle. Honestly, I tend to think one would be better off simply adding 3-3.5" more barrel than the Bulgy 4 piece. In sum, they aren't cheap, they don't offer great performance in terms of flash suppression or recoil/muzzle rise mitigation and they come with a very heavy weight and length penalty.
That is just my take.
