I used this bag 5 consecutive nights in temps from 28 to 12 degrees F (in tent, on snow), slept comfortable to 25, woke up cool at 20 and needed to wear down coat, booties, etc at 15. No neck collar and the zipper does grab material sometimes but releases easily. If you want the Helium, get the EQ model with a less permeable outer fabric... better chance of reaching the temp rating. Still, I wish it had a down collar for temps below freezing. I'm replacing this Helium with a Western Mountaineering Versalite as I do have other WM bags and trust the temp ratings. BTW, the Helium is sewn in China and stuffed in the USA making it quite competitive in price.