I rented a 100-300 panny this weekend and was disappointed in how soft the corners were at 300mm. I would have to do more tests, but I returned the lens, so that will have to wait for another day.
I have a 200mm nikkor f4, but it does not perform well which was surprising to me.
My best solution (sadly) so far is a 70-300 f4-f5.6 nikkor. The "D" version, not the VR version. Surprisingly, the "D" version outperformed the VR version for me. Manual focusing this lens isn't a whole lot of fun given the ring size and placement.
So, I am looking for suggestions as to other possible, reasonably lightweight lenses with reach. The Oly seems to not get a whole lot of love and is expensive. There are no m43 tele primes so far. the 45-200 which I also have is not horrible, but it doesn't make the hear go pitty-pat, either...
I am more than happy to MF, so suggestions as to that end would be welcome. I'm interested in anything in the 200mm f4 to 300mm f5.6 range without breaking the bank or my back (a 300mm f2.8 being right out ).