Luckily for me I really don't like a lot of bass! I have passed over the bass-loving phase and now I just want something that emphasizes the mids and treble, so brighter headphones are what I'm after (NOT Grado bright. I can't listen to those damn things for 15 minutes without fatiguing. I had the RS2i). I do admit that my ears get tired of them after around 3 hours because of the extra brightness, so I use my DT 770 PRO 250 ohm mostly and switch to the T70 when I want a "treble treat" if you may
The HE-500 are my go-to headphones when I want a complete, in-home, low-distortion sort of listening experience. I use a tube-amp with them and would prefer a solid-state to bring out the details a bit more, but I'm not made of money!
I don't find the HE-500 that bright OR that dark. They kinda sit right in the middle for me and therefore are not dark enough to be boring and not bright enough to be fatiguing. Truly a nice experience. The only problem is I am out of the house 90% of the time, so I can't very well bring them around town, so I stick with the T70 and DT770 mostly. I'm moving up to the T5p in the next few months because I'm a BIG Beyerdynamic fan, so that will be a treat. The T5ps are still brighter than some are used to (Especially those HD650 and LCD-2 lovers) but their "Beyer peak" is nowhere near as formidable than the T70s, so I should be able to use them for hours without discomfort.
Just goes to show how incredible subjective Hi-Fi is! Cheers!