This one of the most fascinating TV series I have ever seen. I remember watching the series on TV when I was a small child. At that time, the series seemed scary and I actually believed these stories were true.
Now, when I grew up and watched all the series all over again, I could judge those series with more reason. So, I saw a lot of factual errors. Factuals errors occur not in the actual part which thought to be fictional but in ordinary things.
But I have to admit that the screenplays are written in clever and absorbing way, and that helps to keep viewers interested in this project even after the year when it was closed. Not to mention a great bunch of actors who added sincerity to the series. Their professionalism made these series genuine.
All in all, PSI factor will always remain the classical science fiction TV series, which inspired other great project. So its influence is undoubtedly immense.