Many people love Gmail and many hate Outlook. Not me. I'm okay with Gmail, but it's not as powerful and usable as either the Outlook desktop or Web app. This is the main impression I've had in the wake of the migration: I'm very happy to be using Outlook again.
In the process, I got an unexpected bonus, although in hindsight I should have expected it: Outlook is an excellent RSS reader. It treats the feeds just like regular folders and you can read articles that come in just as you read email. They show up in unread messages and you can easily forward them as email, editing and annotating them. And by putting the feeds in the Exchange account, you keep your reading up-to-date even if you read from multiple devices. Now that I've migrated, the fact that Google is dumping Google Reader is no skin off my nose.
A couple of years from now I might tire of the problems I'll inevitably encounter with Office 365, but I expect Microsoft to pay more attention to them than Google does to Apps. Microsoft just seems hungrier and more committed to its products, which is why they look great and Google's look kind of old, plain and tired. For now, it's a good feeling.