About the weight rating: I did a bunch of googling and found that the 1.9oz ripstop should be good for 300lbs, but I couldn't find a definitive answer. It does seem to be pretty tough material. I'm not sure what to think about the crinkle taffeta yet; I got the impression it had a very high capacity as well.
I've had ~250lbs (multiple people) in my green ripstop without any issues. Only tested the crinkle taffeta to around 215lbs so far, but with no sign of a limit at that weight.