I used my dads when I went to Iowa last year and it was so awesome. It is the best piece of insulated hunting wear I have ever used. The next time I get any kind of insulated hunting wear I will get either the body heater suit or the warmbag. You don't have to put near as many layers on and it rolls up and you can carry it on your back or your stand like I did. Here is the link to the Warmbag. Basically the same, but cheaper.
http://www.thewarmbag.com/Default.asp?Redirected=Y