I finally got my BOA barrel for my Viper M1.
First off the barrel is very well made. It is probably the best made barrel I own. It should last a very long time. The nickel plating is very nice. The barrel is heavier than my Smart Parts barrels. It has a nice port to it and it is very slick.
The barrel is very accurate and I didn't break any balls in it while testing it on the Viper. The barrel is no noiser than any other barrel.
I found nothing bad about this barrel.
If you are looking for an aftermarket barrel for the Viper M1 this is the barrel of choice. I would suggest that anyone who owns a Viper get this barrel. The barrel is so well made it should outlast the Viper.