"Should I uninstall OpenOffice and replace it with LibreOffice, or is it still too soon to tell?"

I think you can install them side by side if you're nervous about it, but I doubt you'll find anything that Open Office did that Libre Office can't do. It is after all much of the same code with bug fixes, improvements and bloat removal (there was a lot of dead code in OO, apparently) Files in all the ODF formats are completely compatible between the two, of course.

For me, Open Office has the feel of a dinosaur about it now.