I took mine off when i upgraded. Along with sample videos, pre loaded wall papers, voice activated dialing, tty (hearing impaired) because i dont use those things. Its really up to you. The more space the better. I have alot of 3rd party apps so thats why it was important for me to remove it.
All that comes in your OS. Once u downloaded the OS.. Use crackmem to delete the xml file and anything ele u don't want. Open desktop manager with your phone connected. It should prompt for an upgrade.
Posted from my CrackBerry at wapforums.crackberry.com