I like the larger handles you've got. Yours also has a better center of pivot than mine, however, mine's knob's make it pretty compact to fit into small bags.
For my larger lenses I have a chineseeeeze gimball which has poor build quality, but is robust and strong. Pictured is a 100-400, but I use it for the much heavier 400 prime, and the duct tape is to protect the L- lense from scratches. It was a cheap, but worthwhile add..(the gimball- not the duct tape)
In addition- I usually keep the tripod center piece completely lowered for stability....only raising it for lighter lenses/no wind scenarios.
