Ayre / Aesthetix hum problems?

I´ve never had a chance to listen to BAT stuff - how is it´s sonic signature and how does BAT differ from Ayre sonic wise?
Btw.: thanks for the great answers so far..

I've only heard the BAT tube gear. It is marvelous gear. Very well built. The sound is superb, very quiet for tube gear. I could easily live with it. But, I made the change to Ayre because I listen ALL the time to either the radio or discs and felt bad about running tubes all the time. The Ayre SS gear is easily the best SS gear I've experienced. I think there is something special about the no feedback designs (BAT SS does this as well). Compared to the BAT tube gear the Ayre is faster, more controlled, and more transparent. But, it is leaner in the midrange, more analytical. If all I listened to was jazz vocals and chamber music I might prefer the BAT. But, I like big orchestral stuff and I think the Ayre wins out due to the control and low distortion. Your milage may vary....

BTW - I have Avalon Ascendant speakers and Cardas Golden Reference speaker cables and Ayre Signature (Cardas) balanced interconnects. Cardas Power Cords

I just have an Ayre K-5xe on loan. Sound is dead neutral, very fast and transparent and tons of detail BUT it lacks slam, body and warmth. So nothing for me..
I´d like to have a pre that combines all ;) So, which is the one to go for.. ARC LS 25 MK II , BAT VK 31 SE, Aesthetix Calypso ?

Personally, I think the ARC would sound the most like the Ayre. I really like my Calypso, but be aware that it sounds poor IMHO with the stock tubes, and while you will get the body and warmth you desire I am not sure it is the ultimate in "slam". You should try it if you can, though. I think the BAT may be the best overall choice, but again it would be good if you can try it. These are excellent units so it comes down to system synergy.

I just discussed with the german distributor of Aesthetix and they state that Jim White of Aesthetix in his private studio alsways listens with Ayre gear - so he shouldn´t have hum problems at all? Would be interesting to know if this story is true and how Jim solves the "hum problem".
Will insert a Hovland HP-100 P over the weekend - hopefully this is a better match than K-5xe. Nagra PL-L (last weekend) was to cold..