The Modaco rooted version also has a few tweaks that allows installed applications to be placed on the SD Card, freeing up more internal memory. It also allows use of a swap partition on the SD Card, instead of using the internal memory. Both of these help with responsiveness of the Hero when you have quite a few apps running. Caching of application data can also be moved to the SD Card (by the Move Cache For Root Users application). You can also remove in-built applications (such as the HTC Twitter client - I use Twidroid as it has been recommended as less resource hungry and more power efficient). So there are a number of reasons to go with a rooted version of the ROM. There are a number of guides to help with installing the custom ROM and it isn't too scary a process - and it is just about impossible to brick because the Modaco installation is pretty much self contained.
