I know what you mean, a mix just sounds so much more powerful loud!
I was always reading about mixing at low volumes on here. So i'd try a low volume, and i'd be like, damn this sounds so unexciting. no power. boring.
But then I realized if you can mix at boring levels to sound good, it sounds SO MUCH better loud. And, I also remembered reading somewhere that your ears frequency response changes pretty drastically when volume levels increase, which explains why things sound so much different. There's no reason you can't crank it up every now and then for a little to check it out. Also, it's long exposures to high sound levels that does permenant hearing damage. So if you're listening at loud volumes, remember to give your ears a break pretty often. And, wear earplugs at shows and band practices. It's kinda funny, how once i started wearing earplugs at my band practices, my hearing actually seemed to come back. We got a new drummer and he has a brass snare that is loud as piss. I was starting to get used to it, but i noticed my ears were always ringing really bad. Now that i wear earplugs, if he hits his snare without earplugs in, it is physically PAINFUL to me, and I bitch at him.
use hearing protection+mix at low volumes. There's a reason everyone says it. It took a while for me to figure out why, but i'm real happy I finally did.