It appears that iOS 11.2 Beta 5 has fixed the bluetooth issues of the iPhone X on previous betas. I never found others with issue, but I had constant problems with bluetooth connections only with the iPhone X to AirPods and two speakers. Looks good now. Thanks, Apple.
Bluetooth Fixed
That lasted about an hour. Then it started failing again - on Air Pods and both speakers. Not constantly - just often enough to bug me.
Today, I finally went to Apple Support on Twitter - which I should have done sooner. They had me do Settings>General>Reset>Reset Network Settings, and it seems to have fixed itto about the 95% level. That is livable.
This fix also did not last. I also tried Reset All Settings without success in bluetooth.
Finally today, after working with Apple Support via Twitter, I restored my iPhone to the main iOS 11.2.1 (Not a Beta) x 3 hours. I will give it 24-hours, and if it is still stable, I will have to weigh bluetooth stability vs using betas - until Apple fixes it.
Bluetooth fell apart again after 4-5 hours. On Twitter with Apple Support again.
Apple did a diagnostic test which showed my iPhone X hardware was fine. The bluetooth seemed better today on iOS 11.2.1, but I wanted my data back. So, updated to 11.2.5 beta 3 and restored from my backup (done with 11.2 5 beta 2) - So, far bluetooth seems normal. Not sure what Apple did, if anything - but it mostly works now.