My Lumia 950 runs almost flawlessly. Almost because some apps starts crashing randomly after using it for a while i.e. WhatsApp, not all the time but almost. But overall, the performance of my 950 is snappier and battery life seems better. Best thing is some apps no longer crash/freeze i.e. AppRaisin.
Also, why is it that most of you are complaining of the bugs without giving any constructive feedback here that might contribute to finding a workaround/solution to the problems? Isn't that the jobs of Insiders, no? I mean, besides reporting the bugs via feedback app.
You people who only complain really should read the terms and conditions of being an Insider. Bugs, bricks, Hard Reset, WDRT, all are to be expected with these builds. Yet you complain. If you can't handle the bugs, do yourself and us a favor. Quit being an Insider, and go back to the Production Ring. Insider Preview builds are clearly not for you.