We had a few top players in South Carolina using the T-series. The #1 woman in the state used it for a few years...absolutely elegant strokes. Played Victor Imperial blue spiral in it. The founder of the first tennis specialty store in the mid-state also used it for a while. Former NC State player and USPTA pro back when there weren't pros on every court in town. This guy's strokes were also smooth and uncomplicated(nothing like MY whippy topspin forehand).
I've told this story before. Yamaha put on a fast serve contest and the three top speeds were hit by A)Former UGA player using a Kramer Auto wood demo!; 2)ME...using a Fischer Superform; and C) a local teaching pro using a T3000 !!! The Yamaha rep was NOT pleased
We even had players using the T-series long enough to wear through the 'wires'. Sent the rackets back(Chicago?) for re-wiring and they came back 'good as new'.
The Wilson T-series was a lot like the early Ford Escorts. No one would suggest they were engineering marvels; but they sure sold one heck of a lot of them!
Another story I'll repeat...after moving to Atlanta in '80, I'm pretty sure I NEVER had to re-string a T-series racket for a customer...they just disappeared. (I've got a half-dozen on hand that need re-stringing, but I haven't found myself in the mood