Just bumping this topic up, having purchased the app today. So far so good, I might say. Gotta get used to the layout, but it's pretty user friendly. Almost everything is there, quick and responsive, well thought-out.
Two shortcomings, though:
-the impossibility to configure two gmail accounts and switch from one to the other like in the native app. I had to re-route my gmail account n°2 so that the messages appear in my gmail account n°1 (under a specially created label).
-The apparent impossibility to set up the application as the default mailing client. It's especially problematic when sending an attachment (photo, etc.). Everything opens in the default iPad app. Don't know if theres a way to change that.