Being the proud owner of a Rubies suit (that's right I said proud, lol), I can say that the Rubies suit is anything but floppy.
I would say it varies between 3-5mm and is very rigid.
I will be gradually attempting to "adjust" the suit for a better fit, as "one size fits most" doesn't really cater for 172cm and 65kg people.
Stay tuned, I will be calling on some expertise.