I'm giving the new Boxer app a go. I've moved the native Mail application off my home page and I'm going to try this for a solid week before I decide whether or not I like it. I'll let you guys know what I think in a blog post later. In the meantime I'd recommend at least downloading it now while it is still free. After 100,000 downloads they are flipping the switch to $4.99
Secretly I'm hoping Mailbox will push an update to their app adding Exchange support and Dropbox functionality. I definitely prefer its UI to that of Boxer.