I ran the blue one on the street for a couple of years without any problems, until recenctly.
The last couple of years I have not driven the car in the rain or at night but lately I have been working on getting the wipers and the headlights working correclty. I was idling the car in my driveway (in D with emerg brake applied for carb tuning) with my lights on and heard my idle rpms drop and the engine started shaking. The first thing that I looked at was the coil voltage inside of the car on my gage and it dropped down below 12v. As soon as I turned the lights off the coil voltage came back up and the idle came back up and it was idling fine.
What I found out was since I was running the constant output regulator and I was applying more load at the in D idle rpms, the constant output regulator was not compensating for the extra load. I bought a NAPA brand voltage regulator and I have not had this problem since and my average system voltage has gone up to handle the extra voltage loads.
My experience with the blue regulator shows me that it was fine on the street for a couple of years and not using any extra voltage loads. But know since I need to use some of the accessories I now need to use the standard compensating regulator.