I have flown many different airlines for both business and pleasure and I have to say that I have no issues flying Frontier Airlines. I worried about them the first time I flew with them since I had no idea if they were a real airline or just some rebranded regional sub-airline. Their hub is Denver, so coming from the West Coast/Mountain West you will probably make a stop here - great airport!
Every airline is going to transport you from point A to point B. Your job is finding out if that transport will be enjoyable and worth the price you pay compared to another carrier. Frontier has some newer planes compared to the competition - this can be nice as they probably won't have as many issues due to maintenance delays. The built in TV for each seat is great to personalize your entertainment and for those long flights with kids can really make the time 'fly'. They offer 3 levels of tickets when you purchase direct through their site:
1) basic fare - no frills. Checked bags cost extra, no TV included (pay on plane), no food included, seat assignment at check-in (most airlines with their extreme discount rates advertise with this kind of ticket price point - make sure you compare apples to apples)
2) TV included in fare, up to 2 checked bags free, snacks in flight, reserved seat assignment
3) meal plus above
That middle option is very competitive with the general rates of other carriers. If you plan on checking any bags, it is going to make the cost equal or better than the competition plus you get the TV included.
If you are traveling with children I highly recommend an airline where the kids have something to do to keep them busy and you don't have to take your chances with the in-flight-movie.
If I have to fly, I certainly have a list of airlines that I am going to avoid. Frontier is not one of them and I have actually enjoyed every trip I have taken with them.
