The lens arrived about an hour ago... 15 min of shooting, the paid actors were in the backyard No deer were harmed in the making of these images, they might have been rewarded with apples, I can't confirm nor deny.
The hummers are still around which was nice to see.
Initial thoughts after shooting with the lens for about 15 minutes.
I need to test the 300 with the 2x against it over the weekend, I'm curious how my copy will perform with the 1.4x on it as I have the 400-800 and love the lens other than its weight and the need for noon sunlight.
The first thing that came to mind was I wasn't thinking about the lens, I didn't think about shooting with the lens. It's so light and nimble, I just found myself holding it for several minutes and not even thinking about the weight. That's not something I do with the 400-800. So.. bonus.
The AF was fast and responsive, again, 15 minutes of shooting.... but going through the distances, it was quick. No issues tracking the hummingbirds, which were in the shade under the porch area.
I'll go shoot with it more tonight and through the weekend... so far... happy with the results.
The images -- all of these are high res shared on Flickr.
I pushed the Auto button in Lightroom... and exported. The sharpening is the default 40 in LR. Feel free to zoom in on the details, no complaints so far. The hummer was about at minimum focusing distance, all shots posted at at F/6.3 as well.
No deer were harmed in the making of these images, they might have been rewarded with apples, I can't confirm nor deny. 
