I hate sounding like a Mother Hen here, but I just wanted to point out one other thing. You mention that you're listening at a much lower volume with your ear buds than your previous phones...but are you measuring this based on an output level on a mixing board, etc.? This may have little relationship to the actual decibels being focused directly into your ear canal, since there is a mere inch or so to your eardrum. In addition, the fact that your ear buds are much better at isolation from outside sources also allows for greater sound pressure levels inside your ear canal. Kinda like putting a cork into your ear and letting the sound waves bounce around.
Food for thought...
-Bruce

I was referring to the output on my iPod, both subjectively and objectively. With the stock buds, I had to crank it to hear anything on the subway, and when I did it sounded like VERY loud music over a loud background noise. It was actually kind of unpleasant, and I was worried about my ears the whole time. With quality in-ear earbuds, though, I rarely had the volume much over halfway, and it sounded like comfortably loud music over a muted background.
I recorded some VERY loud guitar last night (for those of you who've played one, a Dual Rec Roadster in Channel 4 Modern, channel volume at noon, and master probably around 10 o'clock, with a Hot Plate taking off 8db - probably too loud for an apartment, to be perfectly honest, but I'm just trying to work quickly and get my rhythm tracks finished before I piss my neighbors off too much

), and ended up going with my full-sized headphones.
Honestly, my initial enthusiasm may have been a little, well, over-enthusiastic. Earbuds rule for situations where you're recording quiet instruments and you absolutely cannot have any bleed - since they're already basically inside your ears, you need so little volume that there's not much to bleed in the first place. However, for louder sources where bleed probably won't be an issue anyway, the full-sized ones are better at rejecting outside noise.
Still, I'll definitely be using both in the future, earbuds for acoustics and vocalists, regular 'phones for almost everything else.