Their profile thumbnail weren't cropped when imported which is a pain.
No implementation support for Community Builder which has been around longer and has a larger base than JomSocial.
It cost me twenty bucks and I doubt I'll be using it on my site until these issues are addressed.
The new 2.1 release should address every issue you mention here.
Community Builder support has been added for importing avatar and field data on registration. We know it's been around longer, but unfortunately, it's large codebase made it harder to implement.
The JFBCLogin module has also been updated with a "Redirect on Login" radio button to allow you to let the page refresh on login OR send them to a specific page.