Using the back button focus technique I like to have the grip on my 5D3. And the frame of the 1D4, where it is part of the body. Having large hands my ring and little finger would hang loose without. It simply feels more balanced with it. I can understand, if somebody doesnt like it for the extra weight.
If your on the side of the track, I would recommend more then 200mm. So the 300/4, the 100-400. In your lineup I would choose the 135/2. There are some threads on this forum about this lens and how it is appreciated.
Have fun with it. If I may recommend something: my keeper rate increased a lot using a monopod, the older version of an IS. This lens is cracking sharp, so you notice every little bit of motion blur. I love it. Caused very often a grin looking at the final result......
Had to make this decision last fall. Pro G1X: bigger sensor, slightly better IQ. Contra: heavy. To less difference carrying a dslr. Pro RX100: small, fast at the wide end. Contra RX100: no hot shoe. No switchable viewfinder. No filters atachable (yes, but....)
To make the story short: I wanted a much smaller camera compared to my big toys, something I stick in my pocket and forget. I took 9200 shots since last october, and I love it. I take it almost everywhere. Big plus: people are much relaxed when you use this toy.
Find out, which "style" of bag suits you, and then find a dealer to take a look, better, grab them. Put your stuff inside. This should be an advice for all bags someo e wants to buy. Have fun choosing, I have - ahem- 8 bags, and yes- I need them all
Depends on you, what you prefer. I would take the 70-200/4 IS. Sharp, better IS then the 100-400. Didn't dislike the 100-400, but the IQ was - lets say- ok. And 5.6 at the long end forced me often to choose ISO 3200 for a 1/320- 1/500 on a shady day. Have fun choosing!
After reading many pages in the net, manuals it seems the best to keep a LiIon cell between 40 and 80%. The draining it totally and recharge it full seems to "calibrate" a system, so it knows, how many energy is left.
The totally charge/discharge has its origin in using NiCd cells on satellites. They had many cycles the same charge/discharge, and then they weren't able to charge more.
BTW: I once drained my LP E 6, they closed down somewhere around 22, 24%. It seems, your camera knows your cells better.
My 2 - bar LP E6 takes more shots than the newer 3 - bar. As long as I can trust the percentage, the cameras show. I don't drain a LiIon cell till it's empty. Only my 1 - bar LP E 6 seems to be weaker, around 80%. Like Neuro said, some internal counter causes the effect.