Modest: lightweight, fast, integrated. But...it's a mobile-app with mobile limitations. Palm-users will know what I'm talking about.

Claws: full-featured and mature. But...squeezing that into a tablet screen will feel a bit cramped and slow.

I currently use Modest since I do MOST of my major email on my desktop. I just wanted something that allows me to quickly read the latest while on the go. Modest's integration with contacts, faster speed, LED-indicator, and more finger-friendly interface made it the perfect choice. However, there are times I wish it had Claw's offline reading capability (Modest will not download all contents and attachments of an IMAP folder, even if you set it in the preferences), and Claws does a better job of displaying a fully-formatted html email with pictures.

If you have an IMAP account, there's nothing stopping you from installing both. For awhile, I used the default email app as a mail indicator, but would run Claws for reading and managing.

- Jim