I'll keep you posted if I find anything out.
However, the MSI board has 16 phases for VCore it looks like. M.2 slots have been relocated to a daughter-board.
The Gigabyte board is using a thermally enhanced (exposed junction) powerstage, but 10 of them along with a more massive finned heatsink , two 30mm fans under IO shroud, as well as a backplate. Ultimately as it is E-ATX I think they ran out of board real estate.
The Gigabyte page lists IR3578 with 50A:
The MSI board is stronger by far.