Phono Preamp Recommendations

So if I have warts and gray hair and bad breath I need to get the Cambridge as it is obviously a cure-all?

Here're the specs on the system to which it will be connected, in case it changes any assessments:

AR XB in transit, not sure if I will put new cart on it or not yet. Has the factory Shure 91 and a Pickering XV15-400E. The Phono pre will be connected to this table.

Denon DP-7F with Audio Technica AT450 w/ brand new Shibata stylus on the Phono line of the existing preamp.

CD, Reel, cassette & CD Recorder, and ADS D to A USB converter

Optimus STAV 3400 acting as preamp. (on the to be replaced soon list)

Adcom GFA-545 Mk2

JBL LX-500s.

I'm all but decided on the Cambridge. The raw specs for both the 640 and 540 are the best in my price range. But I don't have the option of auditioning equipment so I am trying to balance my research and inexperience with the experiences of everyone here. I enjoy the range of opinions I see in reading both my threads as well as others that pertain to my interests. I am quite satisfied with the replies I get to most of posts.

Thanks to all who took the time to join in the thread!

Got the 640 and really like it. Interestingly enough have discovered by comparing using the same table that the phono stage built into my Optimus STAV-3400 is actually quite good. There is almost no discernible difference at normal listening volumes. Of course the built-in cannot do MC like the Cambridge can.