Many people overreact when they see gs reaching about 6 to 6.5 vertical gs. Several real coasters existed with that many gs, so I set my limit at 7. Yes, 7 is high, but it can be pulled off for a very brief moment. Sustained I would say at MAX 4. Lateral gs depend a lot on the coaster type. Woodies should have lats on turns ranging from about 1 to 1.8 lats, and even 1.8 lats can start hurting if the track isn't very smooth or unpadded trains are used on the rides. For most steel coasters, I would say B&Ms and Intamins never go above .4 lateral gs, but in coaster sims thats just so hard to accomplish, so .9g seems like an acceptable limit for most steel coasters. For negatives, this is the one thats debated the most. I think that coasters never go beyond -1g or possibly -1.1g...simply because of the fact that if a 100 pound person for example experienced -1.1g then there would be 110 pounds pushing against the restraint. I have never felt near that much force on any coaster I've ridden. Also, at -2gs most peoples' eyes explode, due the fact that the force causes most blood vessels in your eyes to pop from the force. So getting anywhere near that would logically cause the smaller blood vessels in the eye to pop. Since there are no cases with people getting eyebleeds on coasters from what I've heard, I'd think that coasters stay far from -2g [;)]