I would think that this would significantly degrade the performance of the fighters, especially since the pre-late 1944 German fighters were marginal in the first place.
It's a trade off of performance for increased armament and armour. Cannon gondolas and hundreds of kilograms of armour (191.6 Kg extra over the standard fighters 145.7 Kg on a Fw 190 A-8/R2) didn't do much for performance either.
Steve