After about 8 years of using Apple Mail on the Mac (that is if you don’t count NeXTMail on my NeXTstep back in CMU), I finally got fed up with it and had to find a better solution to access my Google Apps gmail accounts. It pretty much came down to Mailplane and Sparrow. I went with Mailplane for reasons I don’t really want to get into here. Very happy with it so far. One thing is that there are a lot of stuff in the gmail web interface that doesn’t make sense to have in Mailplane, most of which actually open up in your default browser when you click on them.
To make Mailplane a little bit more minimalistic, you can include your own stylesheet, and it’s super easy to do coz you can inspect the page right there with the webkit inspector inside Mailplane.
Minimal changes, but makes the experience a lot better. I’ve put up the stylesheet here, mostly for @seoulfully to grab and keep up with my changes easily: https://github.com/ayn/Mailplane-Steez