I want to add a longer telephoto to my Olympus kit. I use a Olympus EM1 Mk II and already have the teleconverter. I tend to use the telephoto at the maximum focal length. Panasonic has a 100-400 f4-6.3. Olympus has a 300 f4.
If I use the Olympus with the teleconverter I think i wind up with a 420 mm, f6.3 (or so). In body plus lens stabilization is presumably around 6.5 stops. I have seen and held this lens and subjectively love the build size and weight.
If I use the Panasonic, I get the zoom benefit and essentially the same maximum reach and aperture at the long end. However, I would turn off the in body stabilization of the EM1 and rely on the lens stabilization only. I haven't found any discussion on how effective (estimated stops?) the lens only stabilization is on the lens. I also don't know if the mixed vendors effects things like focus tracking. I have not held this lens. My closest camera shop is 75 miles away and they just picked up the Panasonic line. I am waiting for a chance to get out there.
I tend to use my telephotos at the longest end more than other lengths. I also have the Oly 40-150 Pro (and the aforementioned teleconverter).
I am a hobbyist and intend to try my hand at wildlife, close abstracts, and anything else that the the lens can provide as a creative outlet.
Am I thinking this through correctly? Are there other factors to consider? Does anyone have practical experience with the Pana lens/Olympus body combo that can offer a perspective?