The Gmail iPhone app has very reliable push functionalities and is way more extensive than its apple general mail counterpart.
iOS 7 is adding a feature that will allow downloading data in the background and hopefully Mailbox and the GMail app will take advantage of that. But in the meantime: fetch, get Google Apps for $5/mo, or deal with the annoying wait
P.S. Ironic that your nickname is "gnus" :) (http://en.wikipedia.org/wiki/Gnus)