I've used SEM also. Having used both SEM and Dupli-color,I'd have to say they are similar. At the moment,I've got a can of Dupli-Trim Black color on hand.
The Dupli-color has withstood the test of time on my other GM cars as far as painting the door edges around the windows. Lots of hand traffic there opening and closing the doors.
Rarely do I have a problem with it going on. If I do,it's my fault by something I missed.
Prices are similar,also.
Thanks for the replies you guys. I almost painted gloss by mistake!