just in case you might hesitate to update to v1.0 (stable) on GS290, I can tell you it worked like charm on my device.
I updated via the update tile in settings and did not face any issues at the time of writing.
Phone, mail is working. Will see how roaming/calls abroad are doing in the near future. If I do not give any update here, then everything is fine.
Thank you very much to the developers, tester and project managment helping to make the update such a smooth activity.