Questions Luxman L-505u, L-507u, Simaudio & Classe

My friend recently purchased a Luxman L-550A II Integrated for his Sonus Faber Auditor M speakers (my speakers also) and wants me to look at Luxman. I own the Ayre AX-7e Integrated amp, it is fully balanced and I like it very much. He is very happy with his Luxman Class A amp with these speakers. and believes I would be too.

The Luxman L-507u looks interesting but $7,000 is out of my range ($5k max) and so maybe I should look at the Luxman L-505u. The Luxman L-550A II Integrated is class A, runs hot and it not friendly toward the environment.

It is my understanding that Luxman amplifiers are not dual mono design yet have XLR inputs. My Ayre QB-9 USB DAC outputs balanced and I prefer my amplifier to be balanced with XLR inputs. The Sumaudio Moon 600i (dual mono) looks very interesting on paper but, again, is over my price range at $8,000. The Simaudio Moon i5.3 amplifier looks very interesting but does not offer balanced inputs. The Classe CAP-2100 Integrated also looks interesting and is priced at $5,900 (a little high for me).

Based on my listening last night, my Ayre AX-7e integrated sounds great to my ears and I see no reason to change amplifiers. However, my friend is "taking" me to the store for a Luxman demo shortly and I am interested in hearing your comments on the Luxman units L-505u & L-507u and any other integrated amplifier for my Sonus Faber Auditor M speakers. Thanks