Goldenear Triton One R vs. PSB T3. vs. Spendor D7...

Spendor D Series sounds nothing like traditional Spendor, which has a reputation of being very laid back.

If you like traditional Spendor, you probably will not like D Series. In my case, D Series is perfect, because of the LPZ (in-house made by Spendor). It is quick and lively, not bright (in my opinion.

I listened to 20+ speakers. Bright (or at least brighter, everyone will hear differently) tweeters are Klipsch, Focal, Paradigm, B&W, and others. Not Spendor D series. They are neutral, BUT COMPARED to traditional Spendor, yes, they sound brighter. But that is because traditional Spendor is probably in the lower 30% of all speakers re brightness.

It’s all in the perspective.

I own D7, D1, and SA1. Listen to each every day. IMO, D series destroys the SA1, but as we say, it is all personal preference. Go and listen. Stores mostly open now.

The hot tweeter stuff is a bit overblown I think with the D7. I've owned a pair since February and it really has mellowed out over time. However, if a recording is bright to begin with it will not soften the blow. A bright recording will sound bright because these are accurate speakers. The midrange is also forward, so if you are in a small room it will possibly sound to in your face.

Pairing with Tubes or Class A SS seems to be the way to go given the choice, but I've got a class AB SS amp and don't have many qualms. Just the itch to try tubes!

For what you’re looking for, of the three I’d think the Spendors would be your best bet.  However, in that price range I’d hands down choose the Joseph Audio Profiles over any of them.  JA speakers are outstanding when it comes to imaging, soundstage, and pulling off a disappearing act, and the Profiles benefit heavily from “trickle-down” technology from their pricier stablemates.  Just my $0.02. 

Yup.  Instead of the D series, consider a Spendor speaker from the Classic line.  https://www.spendoraudio.com/classic-loudspeakers/

Shahram
I have both, Rogue Audio monoblocks and April Music Stello ai500 with a built in DAC. Both power up more then what the D7's need. The tubes can take EL34's, might be the ticket.