I wouldn't want to persuade anyone one way or the other.
Over the last month or so I think I have got to the bottom of why I wasn't enjoying my photography that much these days. It is that I was trying for perfection as I have always thought about doing photography as a job. I have now worked out that in all honesty I don't think I do want to do it as a career (even if it is possible to make it a career these days). Once I had come to that realisation the M4/3 camera really starts to shine and photography is starting to become fun again. The reason being that I can now take shots
I like and to hell with the rules. If you want to get the very best shots possible get a pro body. If you are just doing it for yourself to have some nice images to look at and memories of holidays etc then the M4/3 cameras are the top of the pile imo.
I keep having thoughts of what hell am I doing giving up all this lovely gear. But then I think about the fact that I can have a few grand to put into other hobbies and STILL have a great camera, so in fact I don't really lose much. Yeah I won't be able to take shots of a few of the things I can with the mkIV but at the end of the day they only amount to maybe 5% of my Lightroom library so I can live without them.