Got the 89T demo today...hit for an hour or so w/our pro (wife couldn't take her lesson so I filled in).
Very nice, but ultimately I'm not so sure it will be for me. Coming from the my old trusty RDX Mids, and was hoping it would be closer to that racquet in feel than it is.
As others have noticed, sweet spot is very generous, doesn't feel like a 89 from that perspective. Head shape is a little odd (and I go back the Yonex R7, so I'm used to odd Yonex shapes).
The racquet provides a very interesting, to me almost unique combination of a very stiff feel combined with a high level of comfort. It was strung at 60, I string at 55, and didn't feel the additional tension caused any issues.
Hit serves for a bit before the lesson...definitely easier to acces pop w/the 89T than the RDX Mid, spin seemed similar on serves. Probably appreciated the racquet's stiffness most with serving.
Hit hard for an hour (our pro likes to keep things moving) and had zero comfort issues. In spite of how stiff the racquet feels, it actually really comfortable and smooth, not jarring. Dampened w/out killing touch, really well done.
I'm a relatively flat hitter, and what spin I wanted/needed was very easy to get, and if you relax and let the racquet do the work you can hit through the court with ease. Less work w/the 89T than the RDX to generate power on the ground.
Volleys were excellent, easy to punch or hit with touch, racquet felt very maneuverable.
Ultimately, the reason I'm likely to keep using my RDX Mids is that I just find it very hard to give up the wet noodles feel that they are famous for.

I love the flex and give of the RDX, and the 89T just isn't trying to live in that space.
Caveat is that I only had an hour with 89T, and I'm going to hit with it a few more times over the next few days to see if I change my tune. Not ruling out being won over...serves were definitely excellent, ground strokes and volleys worked pretty much from the first few hits, it's just the overall stiff feel of the racquet that is initially not to my taste.
But like others, I can see a lot of folks being really happy w/this racquet. If only they offered a ED version. ;-)