Here we go again!

"M43:

For Pro's: NO

I think this system has matured in terms of lenses etc. but this is not the system for pro photographer (commercial work). I won't elaborate on this."
 From an internet forum.

There's an incredible arrogance I think, in telling people what they should use. Also in attempting to come up with sweeping statements based on no evidence. I've written often enough in the past, if you make your living from photography, the camera you use is virtually irrelevant. When people pay for photography they are interested in one thing only, the photograph. 99.9% of clients care nothing about what camera or lens you use. The vast majority wouldn't know the difference if you told them anyway.

You may have read these before, but for those who haven't a couple of anecdotes.

David Bailey shot a Vogue cover in the early days of digital, on an Olympus E-10. (3.97 MP) He sent them the file (10.8 MB) They said "We can't publish this, the file is too small" He then printed out the image on an inkjet and sent that to them. They duly scanned and published it.

The editor of Professional UK magazine once did a job for Russian Vogue. During the session he took some shots with a GF1, in addition to a "Pro" Canon. Of the 8 shots printed in the magazine full page 3 were from the GF1.

I have a pretty flexible attitude to cameras. I use "Full-frame" - Leica, APS-C - Nikon and m4/3. I pick whichever I think will be best suited to the job in hand and suited to how I am going to approach it.
If I was to classify my most "lucrative" camera system, it would be m4/3, because I use it the most.

So the question of "m4/3 for Pro's?"

If a "Professional Photographer" can't shoot a front cover, an A3 spread or a billboard Ad campaign on a m4/3 camera, then he probably won't be "professional" for long.

There really isn't any correlation between the size of your camera, the size of your sensor and the size of your income.

The only people who seem to be convinced that m4/3 isn't a "professional" system are "amateurs"

The same people who probably think more about what camera they are seen with, than actually "seeing" some pictures.

I, and many of my colleagues, quite happily shoot fashion, weddings, editorial, portfolio, social and advertising photography on whatever cameras we think appropriate (including m4/3) without giving it a second thought.

We've heard it all before. 10 x 8 is better than Medium-Format, Medium-Format is better than 35mm, 35mm is better than Digital, Full-frame is better than APS-C, APS-C is better than m4/3 ad infinitum.

Personally, I use my eyes to decide how appropriate a camera is for what I need to do with it.
I've never once in this blog told anyone what they should use. I've never once said that if you want to be a "Professional" photographer you should use x rather than y, and I never will.

Photographers who are serious about what they do, wish to be judged by the pictures they take and not by the cameras they use. As "professionals" we know that is the case and that is what will happen.

If we know a camera / lens etc. will do a job for us, then we use it. Of all the photographers I know and have talked with, it's often the "Pro's" who are the flexible / curious / experimental ones and the "Amateurs / Hobbyists / Enthusiasts with aspirations who come up with the dogma and the rigidity. 

The more you rule out, the less opportunity you give yourself to be creative.