The 'X' is what's commonly called a 'full ATX board' the other, VM, is a 'micro' board, meaning it's a smaller cut down version to fit smaller cases,
has less PCI slots ... apart from that, there is no real 'difference' in the two specs.
No point in changing the board for the same board ... save your pennies for a better system.
No disrespect, but that board is older than I am.