I absolutely love my TF-89. It is a beautiful gun, hits hard and is relatively easy to cock. It definetely is pellet finicky though. Of the 20+ types of pellets I grouped through it, only about 6-7 did well, with all of the RWS being the best by far.
Mine's shooting about 840fps with RWS H-points and Crossman pointed. With the Crossmans, I'm nearly shooting through my 3/4" ply backstop. A 5-shot group will blow it out. RWS hobbys are a little over 900fps but weren't as accurate. Over the past 16 months or so, I've grilled many creatures and it is my favorite gun to shoot, including my powder-burners. My buddy has a nice shooting range with a covered bench and we frequently have shoot-offs out to 100 yards, usually while drinking beers. Many a bird has met Mr. H-Point by landing on the fence or in the trees or on the target boxes themselves

I have a Leapers mil-dot 4x32 scope with Accushot 1-piece mount and LOVE this combo! No creep with a 2-bolt scope stop and Loc-tite.
I also took apart my trigger and smoothed all surfaces that moved against each other and rounded the trigger first/second stage screws and greased these items. It now has a great trigger with a medium first stage and a crisp second stage. I wish they would have made a metal or at least a better, less wobbly trigger.
This gun is VERY hold sensitive off of any sort of bench. I'm considering a tune but the velocities are very consistant and am wondering if a tune would make it less hold sensitive.