Before you move to Outlook.com... 
I was considering moving to Outlook, however before I began the long process of moving, I found a number of things that you should watch out for. The biggest problem with it before was Archive, but now they've added that, I was sold. Then I happened to find that attachments need the user to have Silverlight. Despite Gmail working plugin-free, Outlook is still using the horrible Silverlight for something that is fairly standard. And it just makes Microsoft look stubborn. Why use an open standard which runs better in most regards when you can use a proprietary, PC and Mac-only attachment system?
Also, IMAP. And Archive features aren't available on mobile, unless maybe you use the horrible new application, which I doubt even has Archive.
I love what Microsoft is doing with Outlook, but i find it odd that it's still not on-par with Gmail, feature-wise. How much longer must we wait?
Edit: I stand corrected. Only happens when Silverlight is installed. Uninstalled Silverlight, and Outlook becomes good again. And I guess I can live with moving email, even though Archive in Gmail for Android is so nice. It's only a matter of time before I move to Outlook. Just a shame about the lack of IMAP and also the lack of GChat, but that's not MS's fault really.