Triode or Ultra-linear? Why?

Several months ago I added PrimaLuna Prologue Mono-block amps and Preamp to my system. Of course, I keep fiddling with the Triode/Ultra-linear switch, It's so easy since it's on the remote. Can't decide which I enjoy most. Leaning toward triode. What's your experience? 


I find my lofi tubed system absolutely needs the UL/triode option. The majority of my listening is records, many are simply too "hot" when cranked 
ocaissionally in UL. Hearing a Les Paul or cymbals at near concert levels isn't the same when I heard the same song 40 years ago.

UL for me is also a "loudness" switch when listening at low volumes.

I suppose  actual system configuration also,determines what you like.

Presently listening to SD "Katy Lied" in triode. Sounds pretty good for an album they hated for its SQ.

After decades of tube and SS stuff I'm way into a Dennis Had single ended pentode amp now ("Fire Bottle" HO, ranted about by me frequently…sorry... ), and although you should use it with relatively efficient speakers to enjoy all the 12 watts each side offers, I doubt I will ever go back to anything else…as with any great amp (used properly) it doesn't care if it's called on to pump out Steely Dan (I still have all my 70s vinyl), or Benjamin Britton or acoustic jazz…everything works, and surprisingly at all the loudness I seem to need…a great low volume sound also, and other than turning my 2 REL subs up or down here and there I have no tone controls (my DAC has filter options, but that's it). Katy Lied indeed, and I like it.
Also, I think tube guitar amp companies should all consider making a little stereo amp…that Mesa Baron was so cool, and if you can buy a USA (Kentucky) hand made tube rectified single ended class A tube (EL84s) amp head like my 18 watt Burris Royal Bluesman (it's royal blue…get it?), which includes a preamp section and spring reverb for around a grand new, these guys are missing the audio geek boat, so to speak.
Yes, the Baron can be run in all-pentode mode, but the sound it a bit harsh.  Don't know why.  I don't think anyone used them in all-pentode mode for long.