Jeff Rowlands Amp and Dac vs. VAC amp and DAC

Yes your summary is fine and there are no problems with your descriptive writing skills, I understand you clearly . Tube preamp with the Rowland could certainly be a very good option. One thing to keep in mind,  you can modify the sound of a tube power amplifier via trying different brands of tubes  (both the output and the input /driver tubes). This is what many refer to as "tube rolling". You can tailor the sound of a tube amplifier. 

One thing I can tell, you know what you're hearing and that's an excellent trait to have. I have all the confidence that you'll choose wisely,  you know what you like. 
Charles, 

rinpoche ,friendly reminder, be sure you are using the appropriate speaker tap (ohms) with your speakers. 
Charles, 

I missed the JR when the VAC was on, and the VAC when the JR was on. Perhaps when I go to hear the IQ both of these differences will be captured.

Given the Sabrina’s impedance curve that I linked to earlier, as well as the listening experiences with the Sabrina that have been described by some of the others, I suspect that the 1 to 2 ohm output tap of the 200iq stands a significantly better chance of accomplishing that than the 2 to 4 ohm tap, and certainly than the 4 to 8 ohm tap.

I presume, btw, that what you listened to today was the Sigma integrated (which does not have a 1 to 2 ohm tap), and that its 4 ohm tap was what was used.

Continued best of luck, and best regards,
-- Al

rinpoche,
My current amp is the JR 625 S2. I always like to preface my comments with, no absolutes in audio and one man's medicine is another's poison. To my ears the 625 S2 is simply outstanding. The midrange is produced with a realism that is hard to describe, it's truly a chameleon that's capable of reproducing whatever is on the recording...e.g if the soundstage is wide or if there is no bass in a recording that is what you will hear. The only thing that I would want more of is power because of my room's dimensions and the size of my speakers. If I had the money I would move up the JR line. 

The only thing that I would want more of is power because of my room's dimensions and the size of my speakers.

Rick, the Monitor Audio PL-500, at least in version ii, has a rated maximum power handling capability of 400 watts, and a nominal impedance of 4 ohms.  Your Rowland 625 S2 amplifier can deliver 600 watts into 4 ohms.

Best regards,
-- Al