I currently have the HP Integrated. I like it a lot. Previously used it with Totem Sttaf speakers. (sensitivity at 87db). Now currently using it with Devore Fidelity Gibbon 88 (sensitivity at 90db if remember correctly). Anyway, the HP Integrated seems really reliable and well built. I like the sound. I would say it is forward and has a lot of "slam" and dynamics. Having said that it seems to be an amp where you can "tune" the sound with experimentation (which I have not done). But for instance when I switched to the Devore Fidelity the vocals are more forward than before and from what I have read you can tube roll to your heart's content to adjust the sound. I need more time with the Gibbon 88's and placement etc before I do anything though. Previous amps were Outlaw Audio and Yamaha - it was a great leap forward (and should be) but instantly heard instruments that I had not heard before and the soundstage expanded and there was great separation among the instruments right away when the only thing that changed was the Prima Luna plugged (i.e. the speakers and placements were the same)
