I have to say it's a dissappointment that you didn't give the apertures used as shots like 'Yeah it's sharp' don't convince me that it is, but that could be because of the aperture. It's so difficult to judge the quality of the lens on the 5D MkII because I usually check corners and borders, and again either detail isn't there or it's not in focus.
One of the biggest 'cons' of this lens is its slow speed, f/5.6 is as slow as it gets in a modern zoom and yet it's not mentioned. At the present time in the Northern hemisphere, it's dark, even during the day. When the sun does shine I'm getting shutter speeds of just 1/50th sec at f/5.6 at Iso 400, you say that it's a lens which isn't suited to lowlight situations, but that can account for 4 - 5 months in the UK and I suspect many other Northern countries, so it's a lens which can be used for 6 - 7 months of the year, the rest of the time it's a paperweight!
Kenya is great for light, but most photographers aren't fortunate enough to be shooting in this light year round.
This lens is so expensive that it's third party rival is the excellent Sigma 120 - 300mm f/2.8 which allows 4 times as much light in ! then there's the 100 - 300mm f/4 again a great performer at 2/3 of the price, the 50 - 500mm OS is a similar price.
It's a shame that you didn't post images with the 70 - 200mm MkII perhaps with the 1.4TC to get to 300mm, yes it's a bit more expensive, but a much better performer and you can use it in low light.
While you were away Photozone posted their review, and it's not as good as people had hoped, certainly not value for the money.