We recently did the 7200.1 to 7200.2 and 861v6/ID40 to v8/ID41 upgrade at the same time, so I can't clearly point to one or the other as the critical source of SQ improvement, but our current configuration is markedly better. I gather the 7ks and 7.2ks are rather different beasts. I'll state the obvious and suggest you listen to the latter somewhere first.

Main: 861v8, 818v3, 8000XE, 7200HCUSE, 7200.2, Roon Nucleus+, Shunyata Everest w/ Sigma XC and Alpha NR's, HD621, Oppo 103D, Panasonic P60ZT60 plasma. RJ45 switch on master SpeakerLink lines to select 861 or 818, Etherregen & ENO AG feeding the 818, M-Links.
Room #2: 5200.2s from M218.