For years I've flipped between various Mac fat clients and the GMail web interface. The web interface keeps winning:
- Outstanding search
- Great keyboard shortcuts (go Vi!)
- Very good use of screen real estate
But the killer is the reliance on a rock-solid Internet connection, and GMail's own slowdowns. Even though there is an offline mode, it is such a downgrade it's not worth using. So if you need to use offline you're in bad shape; same if you're on a slow or lossy connection, or if GMail is having a bad day. Sadly, that's pretty often these days.
Airmail is cheap ($1.99 in the App Store) and super featureful. It coexists well with GMail's paradigm (archive vs. delete, threading includes sent items, drafts). Great configuration options. Visually pleasing. Robust.
There are really only three places where it has fallen short for me:
- I miss GMail's tabs. Those are still the best way to filter mail, and I was impressed with how well that feature worked and quickly became natural.
- Search. Airmail's isn't bad, but nothing is as good at this as Google's own.
- Gmail (with Chrome) has a great feature where you can drop in a picture and it is resized to look good. Lacking that I now have to manually resize my giant retina-display screenshots.