I'm actually happy when listeners find their balance. I tired some very good tube preamplifiers with first the ATC SCM 40As and now my ATC SCM 50As. My personal experience was that the preamps were too slow for the active setup.
When I converted to different solid state pre-amplification, Sugden, ATC and now Luxman, the pace seemed to pick up substantially affecting the attack speed. I do not experience aggressive or thin sound. Your mileage may vary.