Opinions please - Rowland 625 S2 vs Luxman M900u ?

+1 on triode wire labs obsession. My system powered by 4 of them. They bested (in my system) such cables as shunyata sigma HC,cardas clear beyond, zen wave audio, wireworld platinum and some others. Great power cables. You should try them with luxman m-900 before going with different amplifier. I don't think you be able to find upper and mid level refinements and purity going with pass class a/b like 350.8 or 260.8. You have to step into pass xa-160.8 territory or even xs-150 to bit luxman 900 combo.