We're still using an @tabuleapp.com email address for the From header, just setting the from name to be the user's name. This way we don't violate SPF constraints, and we can accept replies to the notification emails.
This is a good strategy. My only complaint with it (and I do it too for some things) is that it can mess up people's address books a little. For example, when I start typing someone's name in gmail, sometimes I get "Joe Smith <a3gfdf33sds32fs@someapp.com>" instead of "joesmith@hisdomain.com"