I've been using them for about a year for practicing both with acoustic and electronic drums.
- On the acoustic drums, they protect my hearing way more than any earplugs I have (even custom-made ones with a theoretically similar attenuation). Of course what I play doesn't sound amazing through all that noise isolation, but I don't really care.
- With electronic drums, I'm very satisfied with how much they isolate the sounds of the pads.
- Sound quality isn't amazing but again, not something I care about.
- They fit my (big) head pretty well and they only start to get uncomfortable after more than an hour, and probably only because I don't have any hair that could offer some padding.
Overall I'm satisfied, as I value my hearing way more than perceiving every detail of how my drums sound.