For my hop from Honolulu to Kahului, I was an a United-marketed codeshare operated by Hawaiian Airlines. HNL is an open airport:
Hawaiian uses Boeing 717’s for its inter-island flights. They feature a first class as well, but for a 100 mile trip, I’m skeptical of the value.
My codeshare meant that I wasn’t able to check-in online or at a kiosk, but it fortunately turned up an exit row seat. I didn’t feel like paying for Internet access while waiting for my flight and Hawaiian doesn’t indicate that its seats are exit rows on the boarding pass, so I almost walked past my seat when boarding.