Some of the differences are: the autofill for Place Descriptions isn't added in the FTMM2. The Merge screen is still the old bubble style (personally I hope they leave it this way). Everytime you add or click a place name, you have to hit the Tab key to finish the operation.
Other differences are the obvious slow merging people, the abrupt shutting down with no obvious cause, and the slow action when creating a filtered list.
But it sure is pretty!