I just got my Sony A7rii and have been playing with it for a day or two. One of the problems I encountered using Speedbooster/MC-11 adapter with my Canon lenses were auto-focus during video recording and also making full use of 5-axis.
So I ordered the Sony FE 28-70mm kit lens, which isn’t the best lens out there but it is super light (295 grams) and I can finally use all 5-axis for stabilization. FYI, if you use Canon lenses, you will either use the IS on the lens or the IBIS on the camera, you cannot use both at the same time and take full advantage of the 5-axis stabilization on a7rii. This would also work great with my Beholder DS-1 gimbal due to its lightweight.