After installing the update over the air, i noticed a few improvements, slightly less lag.. improved audio.

I then tried the CSSU for a few days, although portrait mode is great, i'm so used to using the N900 as it is that i couldn't get used to it, so i did a backup on Ovi suite and then reflashed my phone to PR 1.2 using Maemo flasher.

After this before i restored anything, i updated the firmware to PR 1.3.1 using Ovi suite.

Even after re-installing all my applications, photos, music, videos etc, the performance from the phone has been fantastic. I now get over a day from the battery which has never happened before and there's no lag at all when switching between desktops or menu's