I had them in May... they were pretty good, but I seem to remember the shell being a little chewier than what I'm used to here in NJ in the heart of the season. I actually really loved the Peach ketchup element.
Anyway I wouldn't get my heart set on soft shell crab sliders; Cali grill does try to stay seasonal and September is really the tail end of the season. I'm sure that they'll replace it with something just as great though, so don't be too disappointed!