In addition to the 100+ bug fixes, some UI elements have been updated, as well as an apparently new driver to interact with the PowerVR SGX530 GPU, here are some of the user-noticeable changes that should come with PR1.3;

MicroB (browser), Modest (e-mail) and hildon-desktop (desktop UI) have been updated and will provide a much faster experience, less glitching and reduced process pegging.

Universal Contact Search has improved response time for displaying results.

Audio playback no longer causes abnormal high processor usage, and pause/resume playback after a call is much more predictable and works as it should. In addition, the mediaplayer widget ‘play’ button now works.

Portrait mode transition is faster for all applications that support rotation. Feels “constant” and much more deliberate.

Accounts being forced to error-offline during new network connection has been fixed.

Several fixes to Mail for Exchange. Unknown if Google syncing has been addressed.

You can now enter a lowercase letter at the beginning of a sentence.

Camera and image browsing has less “chop” and stuttering. Feels much more fluid.

Delay added to screen unlocking during alarm or phone call. Reduces unwanted input.