Like anything else.....and a current example being EV's, there are zealots for every new development. How many banged on about Betamax I wonder? My "knowledgeable" friend criticised my choice of an LED TV. "Plasma is the future" he decreed.
Anyway, I will only relate my personal experiences, which are these. I used Dot5.1 in my Roadster for the first few years, changing every two years, but decided to standardise at Dot4 for "the fleet".
In 1990, silicon fluid was a big deal, and zealots were everywhere in classic car circles. My rebuild BV8 had a completely new braking system.......and that meant EVERYTHING. So I had a simple choice to make. I did the research, although the truth is always masked by zealots. I asked around in the clubs & classic car world. The evidence was patchy. Some people had immediate troubles with Silicon fluid, some wouldn't be without it. Without knowing the background details of those who had had trouble, i.e. whether or not they had done a proper flush, there was nothing concrete to go on. It hasn't been widely adopted by manufacturers either, even now, and so in 1990 I went for Dot4 if it was around then, if not Dot3.
It's a personal choice. With regular flushing Dot4 is fine. With Silicon, it may be fine, but I would not fill and forget. But it may not be fine, and that's the gamble I didn't take in 1990.
