I've been trying to get the 4.3 OTA since it appeared in the ASOP. I was finally able to "force" the OTA by following these simple instructions:
1. Go to Settings > Apps > All Apps
2. Find the Google Services Framework
3. Force Stop the app and then clear the data.
4. Go to Settings > About Tablet > System Update
5. The date should now show 12/31/1969 or something like that from 1969.
6. Check for the update.
I had to do this step 6 times, but it finally worked.
Good Luck!
1. Go to Settings > Apps > All Apps
2. Find the Google Services Framework
3. Force Stop the app and then clear the data.
4. Go to Settings > About Tablet > System Update
5. The date should now show 12/31/1969 or something like that from 1969.
6. Check for the update.
I had to do this step 6 times, but it finally worked.
Good Luck!