Frontier would be rough for business travel. They kill routes entirely, cancel flights several weeks in advance, and cancel flights at the time of flight. Also, there are rarely multiple flights to the same destination on the same day. So, there is little backup to make a business meeting.

By th3 time you buy a few late notice tickets on a real airline, then you have lost all the savings.

The general feeling here on the board is do not use them if you really have to get some place.