you happy with the upgrade ... ?
Yeah, the mk3 is a great camera. The focusing system is one of the biggest things and it really does make a difference for low light stuff.
There's lots of other little things that have been changed and added that make it a generally all round better camera for jobs. The silent shutter is fantastic as well as the dual card slots (great for instant backups on jobs).
If you're a photographer that takes photos for a living then it's a worthy upgrade, if it's for personal use then probably not. There was never anything really wrong with the mk2 in the first place, arguably the focus system being the main annoyance I guess.
If you like new toys and gear (who doesn't), and want something that feels next gen then it will satisfy that, it's a lovely camera.