LAMM2.1 with Tannoy Westminster Royal SE Speakers

Did you find them producing the deepest bass as well as more powerful amps? Did you try anything with a lot more power, and if so, did you find that the Lamm went as low?

Easily. The bass from ML21 has "body" and a holographic power. This you will never find with any Transistor Amp.
LSC-2341 – Saint-Saens — Symphony No. 3 In C Minor, Op. 78 ~ Boston Symphony Orchestra, Munch: When I play that record the windows in my room start to vibrate ...

JA wrote in his measurement side bar to Art Dudley's review (October 2004) "Note that the Lamm's low-frequency response is commendably flat down to the 10Hz limit of these graphs".

I am not surprised by the observation above by Syntax.

Regards,

These are very interesting and helpful discussion points. I'm a bit surprised that the LAMM2.1 apparently performs so well. The only other amp I'm considering (read: forgot to include in my initial question) is the Sophia Electric 845, which has slightly more power than the LAMM2.1, but less than the Wavac and Viva Aurora T.

Well, the ML2.1 has a very robust output stage. Output power is only one data, the internal design is normally a total different chapter.
Another superior sounding amp is the old Pass Aleph Design, Aleph 0 monos for example. Or, when you prefer the unique superior sound from Lamm amps with more power, a super choice is Lamm 1.2Reference. Most high powered Transistor amps have a real problem to sound good in their first few watts, the M1.2R is linear from scratch up.
And, all of the above are super reliable... :-)