I already said this in another thread, it's not about switching databases in one project, but using the same skillset across projects regardless of the database.
ORMs just add a thick layer of fluff over an otherwise (mostly) portable language, where I'm concerned. I rather keep it simple between DBs and apps. If there is gross SQL in the app, make a view or function in the database. It isn't rocket surgery but you do need experienced staff to get it right.