We've done quite a bit of testing with the Joomla 3.5.0 release candidates and haven't run into any issues. We haven't done extensive testing with the full release yet, since it's just out, but I wouldn't expect any new issues.
I just visited your site that you recently ran Autotune with, but am unable to find where you can login with Facebook. Can you let me know where I should be looking?
Thanks,
Alex