I would agree with Dave to some degree with his comments. Remember a brake basically acts as a deceleration device to the rifle. Reverse thruster if you will like on an airliner.
In trueth, the lighter a rifle is, the more effect you as the shooter will feel in the level of felt recoil. The reason is inertia of the rifle itself.
For a given load, in a given chambering with a certain brake, you will get X amount of felt recoil reduction in a certain weight right.
If you keep everything constant and increase the weight of the rifle, you will at times actually increase the felt recoil because once the heavier rifle get set into motion, it is effected less by the reverse force generated by the muzzle brake.
The brake will produce the same amount of force no matter what the rifle weights if all things are kept the same but the heavier rifle will be effected less by the brake then a lighter rifle will be.
Now this of course is all dependant on what chambering you are using. In the smaller rounds, shear rifle weight will go along way to reducing felt recoil. In a chambering large enough to really get a rifle moving under recoil, a heavy rifle will "Move" you farther then a light one because it is your shoulder that has to stop the rifle. Its a fine line but it is not really worth worrying about.
Simply put, if your going to have a brake fitted I would do that and possibly a recoil pad upgrade before I start adding alot of rifle weight unless stability in the bags or on bipod is a concern.
If shooting off a bipod, depending on which design you use, added weight can actually decrease the stability of the rifle system. If the bipod used can not support the weight solidly stability can actually get worse.
Just my opinion. If your going to go with a brake, I would not add any weight to the rifle.
One example of what I am talking about is my 7mm AM. I have built these in light 7-8 lb rifles and also in 18 to 20 lb rifles. All fitted with Holland QD or Defensive Edge brakes.
While none of them fitted with a brake have enough recoil to really mention. The light rifles actually give you the sensation of being pulled AWAY from your shoulder while the heavy rifles, with the added inertia and momentum in the rifle give you a more solid feeling bump in the shoulder. Just a matter of the ability of the brake to effect the momentum of the rifle.
Kirby Allen(50)