70-200mm L (EF) vs 70-300 L (EF)

Jay Brookstone wrote:

... but try out the system before you sell your other Canon gear - any of it - to make sure you can live with the compromise.

Why go with micro 4/3 and walk away from 35mm system equivalents?

Because your goal is to dramatically lighten your equipment load but still be able to cover airshows and wildlife. Selling your 35mm system 100-400mm lens and replacing it with a 70-300 or 70-200 will not in any way accomplish your goals. The overall equipment load will be about the same and the gear will be less capable (shorter reach).

"My goal is to be able to travel anywhere in the world, for an extended duration (2 weeks+) with just a carry on." "I'll be shooting a lot of wildlife and the occasional airshow. Even mix of video/photos."

Jay

I plan on holding on to that equipment. Part of the reason for the 70-300 is because I still hold out hope for Canon getting its act together and catching up in the video dept (I know it doesn't matter to others, but it does to me). That's part of the reason for the GH4. The other part of the equation is, no matter how I slice it, my normal canon DSLR setup won't fit.

Going with the GH4 setup brings my weight from about of around 6.5kg (not including extra batteries, etc) to around 3.2kg plus a huge space savings. (honestly, there is a ton more of ancillary stuff that brings the weight up even more for the FF setup but for the sake of argument...)

Also, I think you're forgetting that due to the combined crop factor of the GH4 with the metabones speedbooster, you get a crop factor of about 1.4 which means I lose a little on the wide end and gain a little on the long end (even with the 70-300), plus I pick up an extra stop of light which will be helpful with the smaller sensor. (The fact that the crop factor is right around Super35 is VERY appealing as well...)

There's no substitute for having "been there". And after hauling a ton of photo equipment around the country and world on professional shoots for a decade, I'm aware of the "sacrifices", but I'm also aware of the benefits.

What good is the best camera equipment in the world if I'm so tired from hauling it through wilderness, up mountains, etc that by the time I get there, I'm too exhausted to spend the extra time getting those amazing timelapse shots or great city scenics.

I'm still holding onto my FF setup in case there are situations where there are "accept no substitutes" (and I'll probably get a 5D Mark IV when it comes assuming 4K) but be honest with yourself, when it comes to personal travel and even a good portion of jobs, a GH4 would have been WAY more than sufficient.