Travelled via Frontier from IND to SNA last week for a medical conference. There were 3 scheduled flights from IND to SNA on the day I left. Two had layovers of about 30-40 minutes, and one had a layover of 5 hours. Since I was afraid to book a trip with only a 30 minute connection time, I opted for the 5 hour layover. The plane coming into DEN was late, and the 5 hour connection turned into a 6 hour connection. Most interestingly, the plane we were taking to SNA (Santa Ana, CA) was originating in San Diego, which is probably only about a 2 hour flight in length.
Then, on the way home, I was supposed to have a three hour layover. The most interesting part about the trip home was that it was, I think, in the older part of the Denver airport, in the part of the A terminal that in downstairs. You boarded the airplane by going outside and walking out to the plane and onto a ramp, sort of like how I did the first time I ever took an airplane back in 1978 or so. It was in the part of the airport that didn't really have anywhere nice to buy food, and the furniture was a bit worn out. I noticed that there was already a plane in the next gate to where we were scheduled to leave, at the time I got to the airport. The connecting flight that we were supposed to board to go to IND was late. As a matter of fact, it hadn't arrived yet until 30 min past the original departure time for our flight. And, then when it got there (no disrespect intended), there were more than 5 passengers with wheelchairs that needed to be taken off the plane (via the outside ramp). The wheelchair were in a locked off area, and the staff at the desk didn't have the key, so they had to call for a key. Then, off course, they didn't have 5 wheelchairs, so, they had to call to get them from elsewhere in the airport (remember, this is in the remote part of the airport). By then, it was fully an hour after our plane was due to leave. So, somebody made the executive decision that we would take the plane that had been parked at the next gate all along, for the past three hours.
All I can say about Frontier is that every time I use them, it is like a circus.