Nope, FX3 is completely different from the new Magnetic Selective Ride Control.
The FX3 consists of a dial in the center console. You have three selections: Tour, Sport, Performance
Tour is the softest settings....cushy and plush. Performance, in some cases will chip your teeth if you go over a big enough bump. It is the stiffest of the three settings.
I'm going from memory here and I'm too lazy to get up off my butt and dig out my books, so bear with me:
Within each setting the computer adjusts the shock absorbers depending upon speed. So, within Tour, there are several stiffening levels, within Sport, and Performance, the same thing; all depending upon speed.
The more I think about it, the more I realize that I really should have this information in the Knowledgebase as I think a lot of people are unaware of exactly how the FX3 Selective Ride Control option works. What I've provided here is a rough explanation.
When driving my '90, I normally keep it in Sport which I find a reasonable level to keep the suspension in. If I know I'm going to be coming up to bumpy road, I'll throw it into Tour. If I feel like sowing my oats so to speak, and want to exericse the car, I'll go find a nice, curvy road somewhere and throw the system into Performance.
In 1996, I believe Chevrolet had an RTD (Real Time Dampening)system which replaced FX3. I forget exactly the theory behind the system, but if I recall correctly, the name was actually a mis-nomer because the system did not react in "real-time" there was a delay.
With today's computing capacity, I believe the new MSRC is the closest thing to "real time".