martinfaw
I personally think they are as reliable if you no how they work. All subs require a higher ignition temperature and all subs have a higher tendancy to absorb moisture. If you know and understand these two facts you are well on your way. When I bring ny rife in from the cold I do bring it in the house to a warm temperature if I am not going to use if for a few days. This allows the powder to give up moisture if it has gathered any. The day before I am going to use it - it goes back to the outside temperature and remains in that temp until I am done for the weekend or what ever the hunting period might be.
I can not use 2f powder in a sidelock and get consistent ignition with a #11 or a Musket cap with the temperature drops to freezing and below. I have since switched to 3f and have never had a problem in the cold since. 3f can be tapped out under the nipple very easily if you do not dump the entire load in at one time.