Jeff, your perception of the HD800 is very dependent on what you plug them into. It's a serious commitment to the transducers capabilities. If you aren't willing to go 'all in' in the neighborhood of 1-2K worth of upstream gear, I'd say avoid it or save up. I had to live w/ the HD800 from a DACPort for 4 months while the Super 7 was being developed and built. That is to say, I never listened to them and everytime I tried they were just like the critics say. But I was fine with this having heard the 800 from the DACPort, Super7 and WA5 at a meet.The 800 sounded just as bad as all the stories when I first heard them at the meet using my DACPort. Then I met Craig and plugged them into the Super7 once the crowd dispersed and did a 'wooaahh'. Then found a maxed out WA5 that purrin hooked his PWD into and did another 'wooaahh'! I was in planar camp at the time w/ the T50rp and LCD2. It was after that I did some audio calculus and felt the 800 was the best for me once I felt I had the transducer figured out based on actual experience. It was the last thing I ever wanted to do, build a whole system around one phone. Insane! So I went all in and bought the HD800 and looked at them sitting there for 4 months because they were about as enjoyable as rice cakes. Treble. If you listen medium to low volume, you won't have a problem. That is unless your gear fails to deliver the bass and dynamics to prevent you from cranking up the volume to flatten out the FR. Hoe that helps.
You could always get a pair and poke around with your own mods, but I really can't stress enough how much you'll want to save for a really nice tube amp to pair with it down the road. It will literally change your life and make you a healthier, more optimistic person for the rest of your life. Maybe a slight exaggeration.