No, this is not the only way. You can use the Opie-PIM applications on a Sharp-Rom and then use multisync with evolution.
The Opie-PIMs have to be installed from the sharp-feed of Opie, they will be linked to the original sharp-PIM-icons.
For me, this works great. You can install Ko/Pi in addition, because Ko/PI will import your Opie-data flawlessly. So if you think about switching to korganizer on the desktop from evolution, this would be the way :-)
Have fun,
Kathrin