Triode or Ultra-linear? Why?

I went back and forth, too, on a CAD120smkii.  Mostly prefer triode, now, and usually leave it that way.  Probably 90/10 triode/pentode.  Probably somewhat tube and speaker dependent, too, in addition to musical selections.

Very interesting. Most posters seem to enjoy triode mode. Why not just make a superior triode amp, save the cost of switches and additional wiring? Actually, I think I know the answer. Most consumers are impressed by power ratings, nothing else.

The only tube amps I've gotten along with have been pentode/UL. SE, yet to hear a PP. As you likely can guess I mostly listen to metal, classical, and electronic music. Frequency extremes are important.

I agree on dedicated amps without switches, I like purpose built equipment. Too many options seem to me like a lack of direction from the manufacturer. There are plenty of SET fans out there, I don't see them missing the switch. And it's kinda neat to see what you can pull off with really low power amps, I'd be tempted if it wasn't for the mid-range focus of much of these amps

I had a VAC amp that was switchable from ultra linear to triode and always preferred ultra.  Triode was too soft and lacked dynamics even with my ESP speakers which present a tube friendly load.  Now I have a BAT amp which is only triode and lacks nothing in drive.  I don't believe the switch option provides a fair comparison.  Pure triode sounds awesome at the expense of inefficiency and massive heat. 

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.