Personally, I like Claws-Mail over both the default email client (anyone will tell you they don't like that one anyway) and Modest. Claws-Mail is built more like a desktop client, has many more options for mail retrieval, syncing for offline reading, plugins, etc.

But, Modest is nice... It's just not ready for prime time yet. It will be great to have an integrated email client that actually works -- which Modest will soon be. But, for my purposes (and particular uses), Claws-Mail wins hands-down.

Tim