Jeff Rowland

If I don't think the Continuum is a big enough difference, I will sell my 525 and look for a used/demo 625 mk1....

+1 Almarg, Zd542.
Ricred1, before you sell off your M525 in the event the Continuum integrated is not a major step-up in SQ, do try using your 2 M525s in a vertical biamp config. It might just surprise you SQ-wise - amps driving a higher impedance are generally less stressed & sound better, no matter what the manuf says. (There are a few expensive amps that buck this general trend but these are exceptions).
If it doesn't, so be it, you tried/explored every configuration with all the Rowland gear you had on-hand & it did not work out so you decided to go for the M625 Mk1.
Like Zd542 wrote - you have both M525s & all the cabling (if I understood Almarg's post correctly), it behooves you to try the vertical biamp config. thanks.

I finally had the opportunity to compare the Continuum S2 to the M525 in my own system. I'm 100% sure going to purchase the Continuum S2.

Guido,
I appreciate you sharing you time and knowledge regarding Jeff Rowland products. My situation was difficult because I wanted to hear the S2 in my system, but didn't want to feel obligated to purchase from the dealer that could make it happen. I had to wait until a friend of a friend could help me out. It's funny how we hear different things, you said the S2 was clearly better, while others thought the S2 was only marginally better. I know I can enjoy music with the S2 and not think about my next purchase.

Pleasure is all mine Richard... Reality is that audible beauty lies in the ears of the beholder... And I suspect that you and I might be hearing in ways that are not dissimilar.

Undeniably, someone else,, equally passionate about audio and music, might have prefered M525... Or the house sound of a totally different brand.

Guido