Thought my seat was too high when the ThudBuster bottomed out (apparently the seat post is longer than my bike accepts), but no, it's great! My legs straighten fully if I push my heels down below the pedals, which takes effort; otherwise I've got a good extension without overextending. I sit more firmly on the seat, but not too hard. I moved the seat up 5mm too, which has helped because I was scooting back a lot.
This is much, much better. I thought my seat was already high enough that I didn't want to extend any more; but I think I came 2cm or so higher, and it's fine. If I stand, I stand over the seat by about 4-5cm I think.