I can fully understand why families with many people would fly Frontier. The cost savings across multiple tickets, especially if sharing checked bags, would be too enticing.
That said, you get what you pay for...or don't pay for.
You pay $25 for a checked bag, $30 for a carryon and $60 for a bag that should have been checked, but was not and had to be gate checked. Luckily we paid and checked out bags. The saving grace of these fees is that it was the quickest boarding procedure, both times.
We checked in 2.5 hours prior to our flight because we had no experience with Frontier and weren't sure how efficient it would be...luckily. We waited 30 minutes in the main security line and then were directed to the North security where there were "no lines"...waited 20 minutes there because there was a line (none of this part is Frontier's doing). When we reached the ID and boarding pass check, the young woman who checked us in at Frontier did not exchange our print-at-home boarding pass and it wouldn't scan. We had to get out of line, walk all the way back to Frontier, and receive new boarding passes. Luckily we could cut to the front to have ID and boarding pass checked.
This cost us about 20 minutes extra and unnecessary stress.
As stated before, the boarding process was quick and easy, even for the full flight up there.
On the return, we knew to get the exchange for the boarding pass so getting to the gate went smoothly.
This flight was not full. We were in a seating group of three with a gentleman who really needed two seats. Luckily, we all thought, there was only one person in row 13 in front of us so when the plane was loaded he moved there. He was immediately told that this row requires $50 extra to sit in so he was told to move back with us. Of course, the fact that he really didn't fit was not addressed.
They would rather everyone be uncomfortable than to let people sit in a different row. FYI, row 13 was an exit row and truly had nothing additional to offer...not sure why it was $50 extra.
There was no option for any entertainment on the flight i.e. no screens.
Currently I would consider Frontier to be the Greyhound bus of the sky and we won't be flying them again, even for the cost savings.