Is Thunderbird beta 3 a big improvement?

I gave up Thunderbird after it kept losing all my profiles. That was about a year ago. I was just looking to see if there were any updates. There's a beta 3 version. Has anyone tried it out?
Is it a big improvement from the v2.19 or whatever it was? I'd like to go back to it but I don't want to install it and find it's a crock. Any views on its pros and cons would be helpful. Thanks

 

It would probably be best if you waited awhile. There is a lot of work going on with features and in the core with the new dev group. You don't want to try a beta at this point if your not prepared with backups. IMHO, it's not ready for public consumption right now. Only for testing!

 

Thanks, i will take your advice.