If you wish to have 4K video, silent shutter, a better grip to use with larger lenses, slightly better ISO, better IBIS, it's certainly a worthy upgrade.
I feel the improvement is negligible except 4k video... You can get a better grip by buying a half leather case cost $20 or less from ebay.. Rest all worthless in real life except in paper... It's just my opinion... I still keep my mk1 cos I don't shoot videos... Cheers