Change of address
Surely the most awkward, annoying and time consuming of any such change is letting people know your new address (ok, letting the people who you actually want to know what your new address is, rather than everyone just by redirecting/forwarding so that you can temporarily lower your spam influx)?
Somehow I doubt MS's service will do that for you, nor go through all the sites that you have emails and notifications set up for and change all those. For me that's the heavy lifting that you'll still have to do yourself. Set-up and content migration is normally not too bad, at least if you also take it as a good time for a clear-out and spring clean (and of course also actually download emails to a mailer program occasionally too for the ones you do want to keep for whatever reason).
So sounds like a lot of hope and hot air to me I'm afraid...
Oh and while also letting you set up your Gmail account as a "send-only" account
What use is that, as opposed to just shutting the thing down if you are really looking to migrate? Or did the author actually mean a "receive-only" account (which can also easily be done by just not sending from it I guess).