According to the Nokia Lumia 1520 software update and downloads support page the new build is 1028.3534.1347.2001 however finding out what exactly it updated may be another story.
Here is the list of changes the update brings to the phone:
- General performance and usability improvements
Of course that means any number of things could have changed and after a quick peek around the handset I have not seen anything in particular that stands out as different.
As I use the phone throughout today I will keep an eye out to see if anything obvious jumps out at me about either the performance of the phone or any interface usability changes.
To see if the update is ready for your Nokia Lumia 1520 just tap Settings>Phone Update>Check for updates. The entire process took less than 10 minutes for me.
If you have a 1520 did you notice any changes with this update?