lLet me rephrase my comment. If you are a wedding or portrait photographer, the PPA certificate may be worth the time, money and trouble. Otherwise, it is of little or no use. I don't think there are enough customers that aer aware of this certification, and it just takes up wall space that you could otherwise devote to samples of your work, which speak better to a potential client.

Although I completely agree that there are Zeiss lenses made by Zeiss that are quite good, Zeiss has a history or licensing designs and their name to others, under very strict quality control by Zeiss employees located at Asian factories. There are Zeisss lenses and Sony/Zeiss lenses. I can say that I once owned a Contax G2, made by Kyocera, that had Zeiss lenses made in Asian factories under Zeiss supervision that were better than any other lenses I have owned, Nikon, Leica, and Olympus. Of those, the Olympus lenses were biting on the Zeiss heels, but nothing could compare to the color and sharpness and resistance to flare of the "fake" Zeiss lenses.

Not a fair comparison, Some cameras have stabilization in the lenses, others have it in the camera body. Your Sony may have it in the body.

Simple, you write a check. I've known a lot of professionals, from my days as one, and some had the PPA certificate, which involved more than anything, money, as to get one you had to go to their special school every summer. And every one of them was a mediocre photographer. If you're good, you don't need the piece of paper.

I too am aging, and things were getting out of hand regarding weight and bulk of equipment. I first got a Nikon V1, which proved to be a big steaming pile of crap. I sold it, and got a Panasonic GF3, which was on Amazon for less than $300 with the 14mm pancake. Was happy with the result in general, but recognised that using the chimp screen as a VF is a fools errand, and watched for something with a good EVF to come along. Then, Panasonic came out with the GX7, and I jumped on it, and found it very usable and a maker of good files. All I missed was good multi axis IBIS. Then the Olympus OMD-EM5ii came out, and I got it. It has a better EVF and great stabilization, better than you will find in any DSLR. Both cameras produce files that will easily go up to 13x19, and I've printed some at 17x25 that looked as good as my Nikon D3 or my Leica M9, both of which are too heavy for extended use.

Do it, you'll be happy.