I've taken a couple shots with this combo, trying to squeeze some goodness out of it, with varying results. Besides some inherent softness, it's hard to get a good shot without a tripod, and I use this combo exclusively with wildlife, and rarely with a tripod. I typically am either using a monopod, a car window, or hand-holding to catch a bird in flight.

This is for the curious and those considering this combo. My summary: I can get "keepers" if I am very careful and if I don't need to crop really closely. But it takes some work!