Tested playing the same song 手裏修羅雷 6☆ on 2 handphones Xperia Z2 and Z3 on 2 different accounts. Both with Full combo and Master but the max combo difference is about 5 - 10 notes with Z2 (380+ - 390 max) having lesser notes compare to Z3 (395 - 400). Z2 card are 2 URs and 3 SSR but Z3 is using 1SR (Main), 2 UR+ and 2 UR.
Most funny thing was when I missed 3 notes on the Z3 I still get 400 combo. This was tested over a few days as I was grinding for friendship points with mine and my wife account.
Wonder if anyone can give me an answer to this.