I currently have a HiFiMeDIY Sabre USB DAC and a Fiio E11 amp, and I really don't want to upgrade either. I listen to music on a laptop (mostly either WAV lossless from CDs or 320 kbps MP3s). Portability is not an issue. I will probably use whichever one I choose occasionally for gaming/watching movies, but listening to music is far more important. Also keep in mind that the Q701 is a little more expensive.
Here is some of the music I listen to, arranged in tiers (no particular order within the tiers):
Tier 1 (easily the most important):
Guns N' Roses
Blue Oyster Cult
Hair metal and power ballads in general
Bullet for My Valentine
The rest of my music consists of mostly classic rock and classic metal, with some 90s rock and more modern rock, and a very small amount of rap. If you have any other recommendations, I would be looking for something similar in price. I am only looking for open back over ear headphones. I already have the SRH840, so I am looking for something different (especially for Pink Floyd and other classic rock).