I ordered my KXR back at the end of November and was lucky enough to get it into my system just over a week ago. Right out of the box it sounded great (feeding my MXRs), much better than any other preamp I've ever had in my system.
The parts quality and attention to detail are just outstanding, as is the functionality. Aesthetically and operationally it is the most complete Ayre product yet offered IMO.
If you do a search at Audio Asylum over the past two months or so, Charlie Hansen had several entries explaining some of the functions, the reasons for them, and the intended benefits. In response to a question as to what was a bigger step forward (from the V-1xe to the MXR, or from the K-1xe to the KXR), Charlie stated that he believes the KXR is the bigger "jump". Once I have several hundred hours on the KXR, I should have a better sense of how far it has taken my system, but I have no misgivings whatsoever.
As to timing of delivery for new orders, you should probably just call the factory and get an estimate (303.442.7300 x223 for Michael). Good luck! - Pete -