Triode or Ultralinear mode

"My BAT VK 55 is pure triode and is the antithesis of the other two.  It is dynamic with a pure sound that ultra linear can't quite match.
So in your case, stick with ultra linear."

rhljazz- Is your assessment with the exact setup, but different amps? I would think there are amps that offer UL/triode  switching, and don't kill sonics as you describe? I don't know if your BAT operates in Class A, or if its like the others which are A/B? Maybe that isn't even a factor to consider.....?

My midfi tube amp clearly pushes a band "behind" a vocalist, when listening in triode. Not in an unpleasant way, just different. R&R most of the time sounds more exciting in UL.  A Jazz ensemble with vocalist, seems more convincing in triode. Classical, I leave in UL.

crwindy,
the results partly depend on your speakers. What speakers do you have? db?

My Cary SLI-80 and Cary V12R tube amps definitely do not sound "dead" in Triode mode. I design/build my own custom speakers for fun and have tried various combos.  I've found less efficient speakers (87-89db) do sound better in UL mode with the stock or highly modified SLI-80. Once you go above 90-91+db speakers, you will start to notice more of a difference in Triode mode with your Cary SLI-80. Try it with some more efficient speakers -OR- bring your amp to a place with high efficiency speakers and re-evalute again. It’s possible your speakers are not a good match for your amp in any case. Try different combos before drawing final conclusions.  

I just replaced my Merlin VSMs with Vivid 1.5. 
I love the sound, and have no complaints. This was a question, as I didn't get the so called benefit of triode mode.
I wouldn't trade these speakers for quite a while. I am only at the house with them part time, and every time I go there I am shocked at how great they sound.

When switching between Triode and UltraLinear modes, do any of you speakers POP loudly ?  Mine does and the manufacturer says it's normal and pop-ing is dependent on speakers ! Not sure why... Regardless,  I worry about possible damage to speakers in the long term.

Same is true shutting down the integrated amp...  I first put it on standby mode for 2 minutes, then shut it down... POP !!!  and LOUD !  

To my ears, my SLI-80 siunds better in the UL mode. In the triode mode, it sounds flat and thin, but with better midrange. The speakers are Silverline Sonata-III.