As an airline this is only good for flights where you don't care how far away your airport is from your final destination or you are flying with minimal to no luggage. They aren't that much cheaper when you think about it if you fall into the trap of paying for the tiniest of amenities. The airports they fly out of are usually smaller. Both Mesa and Provo have Allegiant as their only carrier so had something gone wrong with my flight I would have had to wait another day, rather than book it over to another airline in the same airport. Smaller airports save costs but in the long run they may be more expensive.
I am sort of torn, though, because the flight attendants are great at their job and we're far friendlier than some other major airlines. There was a medical emergency on my flight in the row behind me. Except for the FA grabbing an O2 bottle I wouldn't have really known there was an issue. Everyone on board was discreet and kept calm and friendly. They handled the landing well with bringing in EMS, again without panic or fanfare.
I tacked on a star to my rating just for them because there is no way I'll fly this airline again unless absolutely necessary.