Please help me chose a tube preamp

You can do better than Aesthetix.  My limited experience was a friend who had three Aesthetix preamps over about a year.  He had strange issues with each and every one of them.......channels dropping out, eating tubes quickly, noise, leds going out......etc etc.
Get an Atma-Sphere, ARC, CAT if you can

If you want ease of use and reliability PS Audio BHK

I owned a Calypso and purchased based on reputation.I was under whelmed with the performance.Replaced with an Audio Horizons TP 20r which was audibly superior in every aspect of musical presentation.
I'm not bashing the Calypso,it simply didn't meet my needs.

 I had and aesthetix  Rhea signature with a premium tube set at the same time as a Zesto, a herron and a cheap ASL phono. In short the aesthetixs finished last in sound quality, even behind the ASL that was worth about $600 new(it did have mods).  The Herron was first, which I bought new after this experience, The Zesto was second and the ASL was third,  with the aesthetics bringing up a distant fourth.  I was very surprised given the price tag which was by far the highest of the group and the rave reviews they have received. 
I know these are phonostages where as you are talking about line stages but after that experience I would never buy anything aesthetixs. 

Ditto everything r_f_ sayles and sgunther said!

I'm pro Aesthetix having previously owned the base Calypso with premium NOS tubes and currently owning the Signature version with premium NOS tubes.   In approximately 7 years of combined ownership I've never had any problems or lost a tube.