I myself am looking forwards to moving off-of Mageia 1 (due to Kmail) to Mageia8. Trading drives back-n-forth is crazy (and currently trading between 1 and 6 at this time. LOL).
If you are determined to run on 8, I recommend you having more than one desktop available and keep an up to date external backup because there is a strong possibility you will run into something bad along the way and need to revert back to an earlier working copy.
I've run into black display screens, but this could be cured by rebooting, going to another (Plasma/XCFE/other) desktop, then updating until a fix comes, and soon you can return back to your preferred desktop. There might be times you need to revert to a fresh install.
Your best solution is set the update checks from 5min to later, like 3 hours, and only checking once per 24hours, and then resist the temptation to update your PC as soon as updates are available, but you should do it periodically. Before you actually run an update, you need to do two things - first, backup your home directory (you should be doing this regardless of updates or not), and second thing, take a photograph of your harddrive onto a secondary external harddrive (dd is very good at doing this but I recommend using bs=1M to make it go much faster, or alternatively, use clonezilla - use a USB stick with clonezilla, Knoppix, or Mageia-Live).
If all goes well - great - if not, you have a backup and photograph of your harddrive you can revert back to, then wait a little longer for further updates to happen which may get you past this "bump in the road".
On the plus-side, you're right in the midst of all the action, so if there are bugs you see, file bug reports, and be pretty accurate and helpful where you can, so that the final release is as good as it will be when announced