Not sure which Beyers you were referring to, but I have the Tesla T1s and I agree completely with you. Unamped, straight out of the DX100 they could get loud enough, but were missing the fullness, soundstage, and to use your work, ooomph. I now always keep a Ray Samuels SR-71A strapped to my DX100. I find that even with my Heir 4.Ais, they sound better through the amp than straight from the DX100. I'm not complaining about how they sound through the DX - pretty much anything I've tried sounds good through the DX100. They just sound better, much better amped.
I have a set of Heir 5.0s on order and am eagerly awaiting being able to compare them side by side with the 4.Ais and the Beyer T1s.
I was referring to the Beyers in my sig.
I am also interested in the new Heir 5s, I'm interested in your impressions once you get a chance to listen to them...