Distinction needs to be pointed out here...
"Muzzle devices" is a generic term that shouldn't even exist IMO, and let's not use the following terms interchangeably, because they're different animals.
"Flash Hiders" are designed to obscure the muzzle flash (shooter's location at night) and have exit holes you can drive a semi through.
"Brakes" are generally only .020-.040 overbore, meaning concentricity and quality of the machining are critical so that the gases are directed evenly and will not push the base of the bullet off axis as it exits the bore.
"Suppressors" , or "Silencers" require even tighter concentricity tolerances due to their length and baffles. These are classified NFA (for now).
I do know that poorly designed/machined brakes can/will affect accuracy (most brakes will affect POI, but not accuracy) but I have not heard of that happening with a flash hider. Honestly, a flash hider is for tacticool looks unless you're trying to hide your position from the enemy...lose it, and your problem. Put the thread protector on the muzzle or fit it with a quality brake.
The 700 SPS Tactical AAC-SD was factory threaded- I have no idea how they crowned it, but given that it was designed to have a thread protector, or "muzzle device" (damn I hate that word) on it- it wouldn't have needed a recessed crown;; they're primarily to protect crowns that are normally exposed. Yours is most likely the way it left the factory.
Far as a "good brake", this is a worthwhile read:
http://precisionrifleblog.com/2015/08/21/muzzle-brake-summary-of-field-test-results/