Now the phone is little more responsive, has video recording, iTunes, newer skins, can store more text messages, new Java applications & voice recording. All these features depend on the package which you choose to upgrade.
Try it out. Its purely safe. Happy motomodding!
Update #0: The battery runs out a little fast. I guess thats the compromise that we need to take for its features. Also be aware that such software-tampering isn’t supported by Motorola.