Krell KAV-400xi, how good is it?

Hi
My current system consists of:
Krell KSA250
Krell KSP-7B
AudioNote DAC2
Jadis JD-3
Dunlavy Alethas
Not so hi-end cables
I actually is planning to replace my KSP-7B with a tube pre-amp such as Sonic Frontier SFL-2, until I read the Stereophile magz Feb 2005 issue regarding the new integrated-amp Krell KAV-400xi. It says "My favorite krell ever" !! Is it really that great? I am just thinking that by investing approx. $1000 more (after selling my Krells), I can get a brand new 400xi. My question is: Is the KAV-400xi better then the combination of KSA250 + Sonic Frontier SFL-2? I could not compare them as I have no luxury to audition the KAV-400xi. I have tried the KSA250+SFL-2+Dunlavy, I am actually quite satisfied with those combination, but they are old!!!
Please help me, thanks so much.

Regards
Adinata