I heard the Krell gear in Chicago once, at a dealer that also sells the Sim Evo gear. Both are nice...both are different. I find the Sim quite a bit warmer and more musical, but the Krell is a bit more detailed. Both seems similar in their bass, which is expected considering the reputation both have for bass slam and control. Sim does have a ten year warranty which says a lot....but then again, you also have to look at your speakers and find the best match. It's a close call. I would take the Sim for my Dynaudios, and I would also pick Sim for Thiels or JMLabs or Martin Logans, but not for Revels or Aerials...take the Krells for those.