I recently updated my Samsung Omnia to the latest custom firmware (DTHJ6-MCR02) available from Modaco (thanks to Maks Pain at My Samsung Omnia). The ROM removes all the fluff from official firmwares like Shozu and Windows Welcome Center while adding some great programs like Batti (for monitoring battery at all times) and the scientific calculator.
Of all the benefits of the custom firmware, the greatest has to be the smaller memory footprint (70mbs free). This easily frees up the majority of system device memory for faster access to menus, applications and other derivatives. Of special note is how my camera no longer show the dreaded "not enough memory" message.
Below are some added benefits to upgrading (some have already been observed in earlier firmwares):
3 New Widgets: Phonebook, Wireless, Internet Shortcut
3 New Buttons in Touchplayer (EQ, Shuffle, Repeat)
Download URL: Media Fire
Link To Forum: Modaco
Installation Directions: InMy Samsung Omnia
Other Omnia-related articles:
Android on the Samsung Omnia?
How To Use Front Camera
Omnia Wifi Problems
Increase Omnia Speaker Volume
Modaco Custom Firmware