Opinions please - Rowland 625 S2 vs Luxman M900u ?

i didn’t want to throw another product in the mix but if I wanted(I did) either a full sounding stereo amp or better yet, integrated amp with muscle you owe it to yourself to experience the new Dag Progression integrated amp. If you have a pre you love then the Progression stereo amp. I have to say as a very longtime jaded audiophile that the integrated is special. It has Dan’s latest design elements which is not inconsequential. My dealer thinks that it will not benefit sales of the Progression separates. It defines muscle with superb musicality. It’s cool too. FWIW

i’ve had both and have a high regard for them. jeff is a brilliant designer and a great guy to boot. His gear is beyond reproach in all respects. 
Regardless I have been fortunate enough to have a Corus/625s2 duo and a luxman c-900u/m-900u in the same basic system and for ‘my’ taste the luxman duo suited me better bc it was a little brighter which provided more apparent detail as you would expect. if anything my system is pretty neutral with the upper frequencies being a bit soft so naturally out of two outstanding amps the brighter one better suited me. i will say this. i think the Corus is a little soft/veiled whereas the c-900u lays it all out there is a very musical and transparent way. i do prefer the lux pre. i would have loved hearing the luxman preamp with the 625 but i suppose that would have been weird. 

absolutely should be a great match

Dave here’s what I think FWIW. I absolutely would keep that Luxman combo intact. I do not think that the 625s2 is a superior move. I personally had no ‘weight’ issues with the Luxman and would hate to give up their all around superior attributes. If you really want more weight you could pick up a used Shunyata or two which will definitely add weight. I hate to see you count on a power cord though. Here’s a grand thought. Your C-900u has excellent tone controls. Give the bass a slight bump if you want a meatier sound. It’s probably not what you want to hear but that Luxman amp is special.
BTW I never seem to take my own advice. What cables do you use?

one thing dave that i can tell you from experience in house. the shunyata Alpha NR is definitely ripe/full  in the bass region. still i would think that the bass tone control should get it done. i think it’s centered at 100hz which is perfect for fullness. 

What are the salient characteristics of the Obsession? What stands out ? 

just to be sure; you’re talking about comparing Luxman integrated amps to same from JRDG ?