I have the Primaluna Evo 300 power amplifier in my main system ( Tannoy Legacy Arden speakers and MC2300 pre amp). It seems every reviewer and most owners opt for the PL integrateds. Perhaps due to ease of review or system simplicity. I just wanted to share from a power amp owner's perspective.
What the PL offers over most other tube designs is ease of ownership and tailoring of sound through tube swaps. As mentioned by others, the auto bias, and bad tube indicators make ownership a breeze. I had a stock EL34 go bad a few days after the amp arrived. Upscale Audio had a replacement at my door 2 days later. After trying the stock set, I swapped in 7581As, KT-88s, and KT-150s. The 7581A were rich but a little dull in my system, and I settled on both the KT-88 and KT-150 as favorites.
I did however have two KT-150 go bad (working but noisy) in short order, in both cases i simply replaced the bad ones instead of dropping $450 on another quad.
I've owned SS amps from other brands that retailed for more including Pass and Jeff Rowland, and honestly feel the PL is every bit their equal in sound quality. I've yet to own anything close to the build quality of that Rowland amp...I now regret selling.
Best of luck with your decision.