Tube amps under $7500

Absolutely the McIntosh MC275, new at $6500 retail.  I have the first MC275 reissue, the Gordon Gow Commemorative, since new in 1993. Specs are 75 WPC but routinely tests at 90 WPC plus.  Believe it or not, I’m only on my third set of output tubes which are 4 KT88 or 6550’s. The amp runs rather cool for a big tube amp, putting out less heat than my old Krell KST-100 and pulls half the current at just over 3 amps for the Mac.  Stellar job driving several sets of speakers over the years including hard to drive electrostatics Martin-Logan Quests and CLS II.  The amp is true balanced in that the phase splitter (the first tube in this design, a 12AX7) is bypassed and each phase has its own signal path until they meet at the output transformer primary.  That explains the 11 tubes rather than the 7 tubes (like a Conrad-Johnson Premier 8B) that is usual in tube amps with this output.  The amp is designed to converted to a monoblock by simply paralleling the outputs for a whopping 150 watts into 2 ohms  (yes, 2 ohms!) 4 and 8 ohms.  A simple future upgrade if you decide you need more fist.

@hickamore   I had a pair of Legacy Focus paired with a ModWright amp.  Always smooth,  natural,  transparent,  detailed,  excellent bass control.   I had previously sold all my tube gear.  As good as the ModWright was I wanted some of that tube warmth back.  I found the ModWright neutral,  but warmer than ARC tube amps when I tried that route.  I ended up being happy with a 6L6 tube Air Tight amp although I wouldn't characterize it as particularly warm or romantic.  

What I really wanted in the end was different speakers.  I still enjoy the Air Tight,  but wanted to experiment with options for my current speakers.  I was considering a ModWright hybrid integrated, which fits all your requirements except being a tube amp!  Seems like you are pretty averse to tube maintenance though.  I think I would have enjoyed the ModWright,  but ended up with another hybrid integrated that doesn't meet your aesthetic.  Only pre section tubes, but very smooth, pure, natural sound as I expect from a good tube amp.  Maybe a good hybrid could get you best of both worlds. 

If you want romantic sound and mention taking advantage of speaker efficiency,  why not something lowerer powered?  Maybe not single digit,  but 20-30 watt range. Something like Allnic used could fit the bill and check all your boxes if you're willing to wait for silver to be available. 

@porchlight1 @yoder  Thanks to this thread I am now an uncommonly well-informed tube amp shopper. Much appreciated.

@hickamore 

just had a thought:  what about bi-amping?  You could use SS on bass, and would give you more tube choices for treble.

@mdalton Interesting thought that had never occurred to me. I suppose it is a given that no tube amp in my price range can match its SS equivalent on bass? And if bi-amping with one SS device and another very different tube kit, wouldn't I then get into level controls and active crossovers? Remember, I am a lazy listener, not a gadget enthusiast.