My Panasonic 100-300 II real-world review

This review will come in pieces, apologies for that. I just don't have enough time to put it all together in one piece.

I'm afraid the weather was not kind enough to me to do much of birding (not that I can do a good job of that anyway). The best I managed so far is a visit to the zoo on a dreary gray winter day, which forced me to shoot at high ISO (and usually ended up pushing them in post as well). Not to mention most birds were hidden away as there's some plague going on among wild birds

A quick summary so far:

• The first thing I did was to shoot a test chart, which was a huge mistake, as it just made the lens look like it's a complete mess. (I will post some more about that later).
• I find image quality very good around 150mm. In fact, it is noticeably better than my Oly 40-150 R is at 150mm.
• At 200mm, the center is still better than 40-150, but corners are more or less the same.
• Above 200mm, CA kicks in and starts limiting the lens' ability to get really sharp corners.
• At 300mm, the corners are weak, worse than on the 40-150. The center wide open is also worse than 40-150, but stopping down to f/6.3 brings it more or less in line. Stopping down to f/7.1 gives another slight improvement, but nothing big.
• Stopping down at 300mm does not really help the corners much. They start pretty bad and stay that way.
• The lens suffers from shutter-shock on my E-M10. It is my first lens that is affected by this. Anti-shock 0 solves the problem, but that means no burst shooting. No problems on my GM5, which is to be expected. Most of the samples from the zoo I will post seem to be affected to some degree by this. The shots I show here are selected from series. Most of the shots were completely unusable.
• Autofocus is very speedy, much better than I remember Oly 75-300 was. I would love to use it on E-M1 II.
• Zoom action is pretty smooth, but not buttery smooth.
• There is no problem with zoom pumping. The lens stays at the focal length you set regardless if you point it up or down (unlike the Oly 75-300 I used, which just could not stay put). 
• Focus ring turns smoother but has more friction than I am used to. But it allows for very precise control in MF. 
• Aperture change in video is smooth and silent.
• In general the lens is silent, maybe with the exception of aperture clicking in live view (would have to check in more detail).
• I have not noticed slowdowns when shooting in bursts stopped down, but none of my cameras can really do fast bursts, so...
• I also cannot really test C-AF, maybe will try with GM5 when I have a chance, but it's pointless with E-M10.
• As I was expecting, I found that E-M10 is not the best match for a lens this size and weight. Something with a better grip would make the experience much more enjoyable. As it is, using GM5 with it is not really much worse, which is what I start using with it.
• Have not compared IBIS to Power OIS yet. 90% of shots I took so far were with OIS.

I will be uploading full-res real world samples to my flickr album (sorry DPR, I'm not gonna install Flash just for you). There's just a few of them there for now. Most are developed in Darktable, some in RawTherapee. I tried to keep both noise reduction and sharpening to a minimum, as much as it's possible for relatively high ISOs.

I will later also put up some typical "brick wall" type of shots (for those I actually had very good light).

Anyway, here's some samples: