I have not taken IC before. I have been on Cape Air and Silver a number of times and never had an issue. Based on recent experience, Silver has been doing well. Good size planes with comfy seats. They are code sharing with AA. From what I have seen at SJU and EIS, Cape Air is running the small single prop planes. All the regional carriers have gotten bad reviews over the last couple years. IMO Silver is doing better recently. If you want to get actual stats on cancellations and delays, go to FlightAware.

As has been posted here of TTOL, American will start running a non-stop direct from MIA to EIS in June. I'm not an airline person, but I wonder if that will impact Silver's operations as they are probably getting most of their current passengers for the SJU-EIS route thru AA code-share bookings.