I have two Blackstone cars with Sergeant couplers and I’m not a fan. I like the appearance and lack of slinky, but contrary to your experience they do not play well in the least with my other cars that have 714s. They will stay coupled with some cursing, hammering, and bribing but then they don’t uncouple easily at all either. Are these meant to be operating couplers? How do you handle switching and set-outs?
Maybe if I understood the reality behind the hype I’d be willing to convert on a larger scale but for now I don’t get what people like about them apart from appearance.