In any case, it'll be better to make a backup of all important data, including database backup, media content etc.
I am not worried about my media getting overwritten or deleted. I have all that on separate disks, actually a separate machine... I've just not updated myself with how LMCE stores all this info. If it's in the DB, as xml files on each disk or other possible solution.
It makes sense to use the DB since it already exists but that also means that all saved settings gets lost on an update since the most secure update method seem to be re-installation.
Updating the DB and inserting the data again might not be possible after an upgrade. I don't think many end users are aware of if DB structure have changed and so on. I might not be possible to insert the backed up data... It might very well be possible for this update, but what will happen with the next or next again version...
I would guess that I've a few thousand movies in my system, even more music... I've yet not learned how to structure it in LMCE so it is just a mess at the moment. But I would really hate to redo the structuring work in the next upgrade.
I am certain the LMCE provides a efficient way to organize my media, I just need to read and do it. I am just worried about having to redo it at some point... It without doubt a much greater task than just installing KDE and LMCE from bottom. That can be done in an hour or two...