I sold my Tomohawk and Hornet M two months ago while waiting for the new SR-71A to come out. Don't get me wrong! These two are excellent amps by Ray Samuels and are among the best in their own league! Anyway, it proved to be the right move for me as it's now driving my AKG701 to a new level I didn't hear before though with only 30 hours so far on it. Without doubt, the mid is more liquid and soundstage is noticeably wider and deeper. I believe the difference will be more evident after fully burnt-in. I will also try it later with IEMs (waiting for a replacement pair of SE530 from Shure

) in low gain setting.
With a smaller size than the original SR-71, I personally feel SR-71A is quite portable too. At least for me, I have no problems in carrying it around

I would say you won't go wrong with SR-71A if you occasionally listen to full-size phones like AKG701 at home while using IEMs one the road or in the office.