I did! I have the T-Mobile US version. I haven't received any official firmware past GDR2, so things might work better for you...
Some things I noticed:
1. GPS seems to be "Funny"...it seems to randomly stop updating/cause Here Drive+ to lock up momentarily.
2. After I installed the update, I had to hard-reset my phone to get it working again.
3. After you complete the upgrade to Windows Phone 8.1, go into Settings --> Backup --> and delete all backups. Then tell it to do a manual backup. There is a weird bug where the auto and manual backup fails out at 96% unless you do this.
4. everything else seems to be fine.
Hope that helps!