Brightness is base on personal preference and music listening, I used to own both 4070 and O2. I found myself enjoy listening to 4070 over O2 by some sort of music.
LCD2 excels in bass to mid range but a bit lack of extended treble to me. HD800 is very good in image/sound stage but less involving to me. Just to let you know my background.
Let's come back to your question:
- Detail: T1 is one of the best dynamic headphone that excel in this point. So, the overall result of this point will depend pretty much on DAC part of HA-160D.
I'll rate it 7.5-8/10. A dedicated DAC should do a better job.
- Bass/Impact: 160D has good enough power to drive T1 (with high gain output), I'm impressive, toe tapping and moving my head like this
when listen to fusion jazz.
I'd rate bass 8/10, and impact 9/10
- Treble: I feel a bit lack of extended treble (should be better when changing a fuse to audio grade or silver headphone cable), I'll give 8.5/10
I'll give 8/10 for overall matching of this combo, and 9/10 for value of money. I personally believe that T1 should do a better job with tube amp (for one who want to setup rig without compromise).
note that the final comment base on my experience of DT880/Woo WA6.
PS. I just check your rig, and yes it might be a bit brightness to you. however, because of T1 not Burson 160D which give a bit warm tone to me. All these just from 10 mins listening, and I have no time to do some more experiment yet.