no I'm not because I haven't tried this but others that have rooted say re-installing the Coby update took them back to a factory fresh unit.
Give it a try but you will probably have to re-root.
Just to mention this again, coby ships these things with ro.secure set to 0. Also, adbd runs as root by default. I don't think they're too worried about rooted tablets...
If you use Z4Root you can reverse the root procedure at any given time without the need for a factory reset. If you are really worried about it the Kyros has an integrated factory reset feature. When powering on hold the menu and back keys and you will be prompted with an on screen exclamation and android logo. Just hitting the back button after that brings you to a simple text menu with the option to do a complete factory reset.
I would say rooting alone is pretty safe and completely reversible. It's what you do after you root the device that can cause problems!