First experience was great, TTN - STL (unfortunately this route was dropped). This airport is 52 miles from home, about twice the distance as I am from PHL. However, the drive to Mercer County Airport is all highway and about 5 traffic lights. I was able to park about 100 yards from the door and was drinking a craft beer at the tiny bar within 1:15 of leaving home. There were about 10 folks ahead of me in Security. Driving to PHL on mostly surface roads, parking, shuttling to the airport, going through security, walking to the gate probably takes 1:30. Needless to say, I'm a big fan of Frontier and TTN. Until something goes wrong.
This airport is about the size of a bus terminal and does not have jetways, so we walked up ramps from both the back and front of the A319. Amazing how fast boarding goes when done this way. An uneventful flight both ways, the RT fare was around $130 or less including carry on luggage and seat selection.
About two weeks ago I flew TTN-MDW and my biggest complaint was the wonky website, it took me awhile to print out my boarding pass. But my RT fare with luggage was $104. I parked even closer to the front door this time.
For anyone using TTN, there is a little family owned Mexican place about two miles away, awesome burrito, but a bit of a mess to eat when driving.