It's still work in progress, I guess that's why it's still called "Insider Preview".
The OS is pretty stable, but Spartan == Microsoft Edge crashes regularily and overall is far from being complete, with most of its quite minimalistic UI still missing.
The user interface is still being refined, with Control Panel applets being converted to PC Settings app, and new Universal Apps replacing old system utilities.
WDDM 2.0 drivers are at alpha stage, so don't expect your games to perform good or even run at all.
Also, build updates take about 40 minutes to complete, because they're backing everything up in Windows.old on each run.
So if your only needs are Internet browsing, install Chrome and then it's OK for everyday use. For everything else, stick with your current OS.
If you still decide to try it, always install preview builds in a separate partition, do not overwrite your working OS.