I'm a huge fan of the metal python personally, they won't potentially break or crack in cold weather. Your running it on a bolt gun so it will never get hot unless your doing something completely stupid.
I do have the stricta cords on mine but its definitely not needed for a hunting application. I have about 6 or so of the metal python with the cords and my next ones I order won't have them as they won't be used for any rapid fire or long strings with heavy recoiling rifles.
IMO they are the best and I own about most all major brands of covers.
_________________________
Been there, done that many times and have the DD214 to prove it....