I own the Pinnacle. I run it with a pair of LCD2. One of the earlier versions w/ foam headband.
I have owned and extensively heard the Ear HP4 and a B22 I purchased from a fellow Headfier (n_maher).
All 3 amps are fantastic.
One of them is much more expensive than the others. Even when combined. The Pinnacle.
Guess what. I have zero buyers remorse with the Pinnacle. None.
If I had another $10k in discretionary money and wanted to get an office rig, I'd get another Pinnacle. Its that good.
I'm using the stock tubes as well, I haven't gotten around to tube rolling yet. Too much music to listen to.
I am not looking for some cheap approximation of great music, I am looking for great music. This gets me there.
Coming home from work and putting on some music is the highlight of my day, and now that I have the Pinnacle its better than it has ever been.
For whatever its worth.