I just spent the day at the San Francisco Head-Fi meet (Headphone.guru coverage coming soon!) and there were several <$5k amps in house. An Evolution level one would not be out of place as the market goes upscale.
We would never see you again! Truly a lot of top of the mountain headphone awesomeness with that group. The Headtrip is a beast. Jeff produced an top level amp. As you experienced though, each has their particular points. The Neo is in between the other two sonically.
They are two of the the three best I have heard with the Abyss. The third was the Liquid Gold. Plenty of quality power from all three. Specifically talking about the Abyss, the Headtrip was my favorite with them.