I had the uber, fantastic low end. The mkiv can hang, suprisingly, though. If you boost the uber, that is. Otherwise its the same humongous loose lowend like the recto. I can't stand that personally, so I boosted my uber. Very raw and gritty in a good way, with a slight haircut almost like a Soldano or VHT, but more saturation and more palm mute grit. I liked my 5150, Vh100, and mkiv a bit better though, they had more of a fullness to it. Weird, I know. But true to myself.