Among other things, tripod balance gets an upgrade. Perhaps the only other thing Fujifilm have left to address is price. Press release available at Fujifilm's global site.
“In addition, the grips both provide a little extra height, to ensure larger lenses don’t interfere with tripod mounting. Finally, both grips feature flanges to allow direct connection to Arca-Swiss compatible tripod heads. Like the existing HG grips, the MHG models also provide a more substantial hand grip. The MHG-XPro and HMG-XE are available now priced at $150 and $130 respectively.”