Frontier is fine as long as you know in advance what you are getting yourself into. Like most domestic airlines, you pay extra for checkin baggage, but Frontier goes the “extra mile” and you also pay for carry-on as well, save for a small backpack. I would perhaps invest in a Scotte Vest or hoodie to save on luggage costs. All kinds of extra little charges, familiarize yourself with them. The seats generally have narrower pitches than most airlines and lack much cushioning. Other than that, it’s a pretty decent airlines. I fly to Denver a lot and a lot of times I can get a RT flight from California for under $80.