In response to Jmcgrogan2's comments:
1) I agree that it is one of the most neutral preamps, although I will be honest and state that I have not heard all of the ones on your list. The reviews I have read seem to support this statement.
2) My opinion is that when a preamp/amp is termed musical, it introduces colorations into the sound.
That being said, there is nothing wrong with being muscial or having colorations, if that is what you want. (I know, and have owned, several tube preamps that sound wonderful that have had colorations.) Your post, however, stated that you wanted the most neutral preamp possible.
If you want to introduce colorations into the system, I think you should consider some of the better tube preamplifiers. (i.e. CAT Ultimate, Hovland HP-100, ARC LS-25 Mk II, or a used ARC Ref. 2 Mk II, etc..) All of these sound very musical, and are every bit as good as any on your list, some are likely better if you are looking for a "musical" preamp.
I went with the Ayre because I was looking to reduce my noise floor, especially with my phono stage, and still get a very neutral and not clinical preamp. I got tired of living with the low level noice that tubes produce, even though I had a very musical preamp and phono preamp (ARC LS-2 & PH-3). If you are using a turntable, I highly recommend you give it a shot (along with the CAT Ultimate and the Hovland HP-100, all of which have very good phono sections, although the later two do not have remotes. In addition, I went with the Ayre, because I wanted to get a remote, so I could adjust the volume from my listening position.
My two cents worth anyway.
Good Luck in your search. It took me awhile to find a preamp that met my criteria (which was a little different than yours), just a couple of weeks ago. If you want, you can contact me in a few weeks to see what a more extended listening period does to my opinion.
PS One more thing. Why are you looking to buy NEW? Why not used? Let someone else take the depreciation hit. Typically you lose 1/3 the price just walking out the door, not to mention sales tax! If the unit is actually used for any period of time, the price drops down to half or less. I purchased my Ayre K1-X, with phono and remote for $4000, which is less than half the list price of $8,600. Just a thought.