Hi @BernhardWStudio,
We're making big changes, so there will definitely be refactors that are required, however we're making a big effort to release things with a migration path, and to do it in pieces so you can upgrade a step at a time. For example, 6.4 is shipping with the XY-Grid, but you can still use the older grids, and in fact you can even use the older grid in conjunction with XY for while you migrate.
We definitely feel like we flubbed the migration path from 5 to 6, and we're putting in a ton of time to make sure that the 6 to 7 migration is less painful.