I have purchased similar pair about 2 months ago for my sister that cost few $$ more and I don't see any difference between them. Same quality, same stitching as if they come from the same factory. You will find review for those pants if you click on my name.
There is no easy or fast way of losing weight and these pants are not magical but they do help with the process of weight loss. You don't need to go to gym or have a gym equipment to exercise. These pants will make you sweat crazy just by doing your regular house chores. If you enjoy dancing, just put your favorite jam on and dance like nobody sees you.
These are basically made of rubber and some people do get reaction/irritation when it's in direct contact with the skin especially while sweating. I would advice wearing thin cotton leggings underneath if you having reaction. My sister did not get any reaction. But I do recall while ago after my firstborn I was wearing neoprene belt trimmer and I was getting red bumps so I was wearing it over a cotton tank top and did not get any bums afterwards
They smell funky right out of the package but the smell goes away after airing them out.