Hi,
I used internal mufflers long enough to know I didn't like the effect they had on tuning and playability. Annoyed with their rattles and creaks, and general uselessness (to me) I have removed them consistently from my drums (only mine) since -- uh oh -- the '70's some time. (All hardware safely stowed in yogurt containers. -- yogurt another 70's innovation....)
I have returned to the idea (semi reluctantly) of felt strips on the kick, which I also abandoned in the '70's. I am still not thoroughly convinced on the felt strips.
Personally, I still prefer muffling that sits atop the batter and can spring or bounce off the head on impact. Don't mind the moon gel stuff, or the occasional bit of tape, and while zero rings appeal to me theoretically, they get tangled up in my brushes.
Patrick