Heya,
The HTF600 is fine. They're not huge. The drivers are big, but the cups are not monstrous. They're a good size. Normal size really. The don't leak nearly as bad as the internet has made it out to be. They leak a
little more than a really good isolation closed-back headphone, but that's leaking
out, they don't leak hardly at all
in. So you're in your own world with them. They're fantastic for gaming, they have a good sound stage and imaging, and the bass is terrific for ambient sound in games and action and is out of control good for anything with a good strong 30hz kick to it like bassy music. As far as I'm concerned, in this price range, nothing is going to handle it except and IEM. If you want to move up in cost, the M-Audio Q40 would be the next tier stop.
Size of headphone for reference (they're not huge like Fischers/AudioTechnicas):
Full review in my signature if you want some more gushing.
Very best,