New speakers for 15*12 room powered by Lamm 1.2s?

Giving it some more thought, if I’m you I’d strongly consider doing a trial of one of the excellent tube preamps out there today as you may find that alone could breathe new life into your excellent Thiels. Preamps are critical IME, plus it could be a lot cheaper/easier than changing speakers. Specifically there’s the new Spatial Audio Raven preamp and the Aric Audio Motherload (both offer trial periods I believe) that could be fairly transformative compared to going direct from your DAC. Just another thought and potential way to go.

Another vote for Rockports ! Amazing speaker! Good luck!

Borresons are hard to place just like Raidho's.  They need room to come alive.  If you can't get 9' between and 3' to 5' behind the speaker, they will not be at their best.  

If you want something that will be less bright that will be elite, look at Wilson Benesch, Rockport, Marten and Stenheim.  

I like the WBs best but am heavily biased since it is what I run and I am a dealer.  Brian may be at that show or if you can visit him in SoCal, it might be worth the trip.  The Discovery 3Zero is more than enough speaker for that small space.  

Rockport's smallest model, Marten Parkers and I don't know the Stenheim line that well but know the sound will be right for you.  

Full disclosure, I am a dealer for WB and Raidho, I have no relationship with any of the other brands listed.  

Jeepers. Room size with dialed in treatment and Theil 7.2s. Can I listen to please? On paper a presentation that’s near perfect. Coherent AF. (Bob) put his finger right on it. You might need to decide how much of that perfect timing is critical. Many of the other speakers listed here and the Borgs that you mentioned are mazeballs. They are better then the 7.2s at many things. But not coherency. Make sure you can live with this. For me and my sensitivity, it would be a completely different listening experience. Not better or worse, different. The Wilsons are a good choice. Why did you take them off the short list? Value proposition?

I'm with Soix on this. I'd start with a trial of a high quality tube preamp. Thiels are NOT bright!!!! But they do expose what's in front of them, mercilessly. I'd also check to see if your cables are a good match with Thiels. I was a happy Thiel owner for 33 years.