I don't think I've ever seen the Pocket Cap pop up on "favorite cap" conversations. It's actually my favorite outline cap. While it can have a fuzzy "anti-style" look to it when sprayed from a certain distance from the wall, it can be very clean if spraying close and fast.
It also has the benefit of the line width not changing much when the distance from the wall changes. I've always liked it for the corrugated metal fences, ridged trains and things like that. I also really like the old school graffiti look it gives to throwies when using it for outlines.
In the 90s, there were a couple options for caps and they didn't work that well on Rusto, so I usually ended up using the stock caps on them. When things started to change, and more caps became readily available, I found myself looking for a stock cap style cap for modern spray cans, but was having trouble finding them.
Once MTN started shipping some of their products with these, it filled a missing gap it the cap selection for those that liked stock caps back in the day.
FULL TRANSCRIPT
Lot of people hate the pocket cap. It's actually my favorite cap for outlines at a distance, it sprays a fuzzy line, but if you get close, you can get really clean lines and really thin lines with it. Another thing I really like about it is, if the distance between your spray cap and the wall changes, the line width doesn't change that much. I really like how it looks for outlining throwies, just has an old school kind of look to it that I really like, but I also use it for pieces. I did this whole piece outlined in pocket caps, no cutbacks or anything. And you can see you can get pretty clean results with it.