Like many out there, I migrated from Thunderbird 2.23 or whatever version came with Ubuntu 9.10 to Thunderbird 3 the day it was released. The upgrade went painlessly for the most part. I also installed Thunderbird on my Linux Mint 8 USB jump drive. I really enjoy this new version, and must say it’s about time for an update.
Since the initial migration from Evolution to Thunderbird, I’ve never considered moving back. Thunderbird 3 is solid, reliable, multi-platform (Mac, Linux, and Windows), easy to use, and has a clean interface. I’ve installed the following add-ons: Quicktext 0.9.10, Silvermel 1.3 (theme), Lightning 1.0 pre, and Provider for Google 0.6 pre (both had to be download from Mozilla FTP site). Everything installed with no problems, and since I already had Quicktext installed before, all my signatures imported easily.
I think my only gripe, like almost everyone, Lightning should be included by default with Thunderbird. Why have an e-mail client without a calendar plugin?