Personally I'd love to try it, but all my work email is on Google Apps, not GMail, so no dice. I wish they had prioritized this because for me Inbox makes no sense for a low volume personal email account, which is what I use GMail for.
I get a lot of sensitive information in my work email; if I forwarded it all to a second account where my employer couldn't enforce things like two-factor auth I'd be in a lot of trouble.
