Woa, thanks for the detailed review, it really is a mind opener. Unfortunately I live at oversea so demoing is not a choice - Volkl and Yonex aren't popular here.
From what you wrote I feel that VCT89 is more suitable for me; I have a style that love to shot into narrow gap, have adequate spin, 1HBH and welcome any help on serve. One thing very good on X10Mid is that I feel that I can use it longer (to my 40s perhaps) with its larger sweetspot and bigger power.
It would be nice to hear other's opinions too.