It's good to see a lot of people coming around to the circle crab thinking. Not meaning to take credit but as far as I know we're the first to apply the hook design to flies in a way that concluded that crab flies were the right application for them. Lately I hear a lot of folks saying that same thing back to me. That's good!
Last year I noticed many, many people using crab flies out on Monomoy. Gone are the days when people like Steve Robbins were pioneering their use on northeast flats. I also noticed that prior to last year, stripers would be veritable suckers for crab flies. My theory, although unscientific, is that the explosion of crab fly use has conditioned the fish to look twice before eating. They certainly still follow, but the rate of crab fly takes has drastically reduced for me and the folks I have taken fishing last year using the same patterns. It's taught me to be better with sand eels and juvenile squid, which is a good thing too. My flats sand eel trickery has dramatically improved as a result.
To answer your question, I am not big on shrimp patterns although I do use them and carry them in case of a sip-fest. The one time I wished I had one more than any other was when I found a pod of squeteague sipping shrimp at a river mouth. I did not end up hooking up, but am confident that a good shrimp pattern would have changed this outcome.
As far as stripers go, I don't associate shrimp patterns with big stripers... this could be a fault in my thought process but it's an honest admission. Maybe others can answer this question better than I?