Thx.. and yes i dont want to make a triatlon, i want to make good pictures and have a good time
Now i have changed my gear in the backpack and tried it on..it`s simply better to wear it on my shoulders and move, than the trolley is.

PS:
And i have tested the last days my new 100-400 II, a really fantastic lens:
quick, wide open very sharp and a stunning stabilisation.
NO, absolutly no comparism to the old Version. The Old Version is also sharp, but all the other things are another world...
ok the Version II is expensive enough for a 5.6 Zoom Lens