I've noticed alot of numbers are being bandied around here. At least provide some proof when you claim a particular ride hits a particular G-force peak. -2.1 for El Toro? My foot!
There is alot more skill (and comfort in real life) involved in having sections of strong sustained forces (of around 0.8 - 1g), rather than random sharp spikes of them anyway!
It's useful to compare forces on rollercoasters to something you can experiment with in real life. For example:
-1g airtime is like standing on your head;
1g of lateral force is like laying on your side on the floor.. etc.
Imagine doing the latter, and then having someone of equal weight lay atop you. That is what 2g laterals feel like, and I really doubt you would experience that anywhere!