I have two DAC/headphone amp : Mytek Brooklyn Bridge and RME ADI FS. I got a Soloist 3XP since last april which is plugged with the ADI FS. The price was fair and I wanted to test its considerable power in replacement of the RME's headphone amp. I wanted to try more power in order to drive a LCD3 and HD800s. And my ears tell me it's a successfull match. The Soloist being class A, it brings out some slam and control to the bass while bringing some depth of the soundstage. 800s sounded meehhh on RME's amp. With this combination, or any upper tier powerful headamp, I'm kinda sure future headphones will be driven properly (Hifiman, Audeze or upper Focal).
I chose the Soloist, for instance, because of the amp mode which relieves volume control to the one on the RME. I haven't tried yet pairing it with the Mytek. I'd rather get another amp, maybe Liberty THX AAA, in order to get the same benefits than RME/Soloist. The Mytek Bridge's headamp has a better sounding quality than the RME's amp. But it also lacks the oommpphhh to drive the 800s and the LCD3 properly. Power is a wonderful corruption !