Upgrade to Macintosh MA7000 or Luxman L507u?

Don't think you could go wrong with either one. The Luxman having both MC and MM phono , the Mac just MM. The Mac has twice the power. Perhaps not big factors in any case.
Having the McIntosh MA6600, the integrated model just below the MA7000, can only say I love it. I have all but retired my tube integrated as I love the sound of the MA6600 so much. In my quest the Luxman and Accuphase were on my list as well. The availability for auditions for the McIntosh and my long desire for the brand among other factors made my choice more the right for me.
Good hunting, post your choice.

Thanks for your comment, glad you are happy with your choice. I'll let you know mine when I make it.

Why not consider the top of the range Luxman L-509u?

The 509u is of the same class of the MA7000 and is in a similar price, not the L-507u which is a mid-range integrated, more comparable to the McIntosh 6500, not to the 7000.

I own the 509u, has a very balanced and natural sound, detailed but never "hyperdetailed", great control of the woofers, deep bass, great ability to play every genre of music (I prefer rock, fusion and jazz) even at high SPLs, deep and wide soundstaging.

It has tone controls but I don't use them, it sounds perfect in Line Straight mode.

Source is Luxman D06 SACD player, speakers are B&W 803D, power regenerator is PurePower AVPS 3000, cables (power cords -even for the PP3000-, XLR interconnects, two pairs of single wire speaker cables in external biwiring configuration) are all Cardas Golden Reference.

Thanks for comments. Does anyone have experience with the Musical Fidelity A5 which I have in my system now? In considering replacement for it, I would like opinions about whether others also perceive the A5 as bright - I don't want to go from one bright amp to another one.

The A5 is a nice piece. For me, I would chose the Luxman over the Mac.