Looking at these specific preamps give me your opinions

Of the preamps listed, I can comment on the LTA microZOTL, as I have this in my system. I think it is a spectacular preamp. Not warm sounding, but very natural. Excellent dynamics and very open sounding. I run it with a Pass amp and could not be more pleased.

I also just rolled in some new tubes to replace the stock tubes it comes with. I thought it sounded good before, but it was next level afterwards. Better top to bottom extension, more organic. A real winner for my system.

cbrez: What tubes did you decide on for your upgrade replacements?

The Townshend Audio Allegri Reference Passive preamp is very good. Not true balanced though but that keeps the circuitry to a minimum. 

@cbrez ​​​​​​

I bought my MicroZOTL preamp lightly used and a little over a year old.  The previous owner said it came with Trigon 12AT7 tubes. I tried them and didn't like them.  He had purchased some Telefunken tubes {not cheap} and I bought them with the preamp.  I've also tried Philips, Siemens, and Brimar Yellow T.  Siemens came in a close second to the Telefunken. These are all 12AT7 type tubes. 

Perhaps you should take a look at VAC preamps.