Some folks here say that either the 4d100 is the successor of the 85, more recently, some say the yonex core 89. but curious how most of the opinions agree that none of the recent tour90 (at least after the k90) is a worthy successor of the pro staff 85, so in my humble opinion, there are a few good modern mids out there. its just a question of geting one that fits your style of play. I still think that the swiss guy might make the change to the 98 sp inch frame, those are good too, just look at the recent ig prestige pro, and now the pk qtour, both amazing frames. but for his style of play, the tour90 is like a taylor made suit.
if that raquet can be made to endure the game as it is today i do not know, i do know that everything changes, everything evolves, and nothing is ever the same as the years go by.
whe get older... our parents die... our kids grow old and move out
and even federer starts loosing some, but as a secret that every one here knows, hes not done just quite yet!