I have a package of the softies somewhere but just never got around to using them. I thought I would try them on my acrylic stems but they are already thicker than my Vulcanite stemmed pipes.
The MOST comfortable stems made, for my tastes, are the fifty cent plastic stems that come with Missouri Meerschaum pipes. Sure, they don't last long if you're a clencher but they're cheap to replace and soft to the bite.
I still buy the Forever stems for my most regularly used cobs, Freehands and Generals.
I like Vulcanite on my briars for comfort and durability but I like acrylic for style and ease of maintenance. After 30 plus years of pipe smoking (off and on), I still haven't decided which I prefer and it hasn't made a difference in a purchasing decision.
Pax