I have been on this airline a few times and they are a budget deal. I got some great rates to Dominican Republic and one time to Guatemala. Two important things to remember 1) Many of their flights stop off in Miami for a layover. Most flights from Vegas (and possibly the west coast) have you arrive at like 7am in Miami or ft launderdale. I had two layovers there...each layover was 6+ hours. Not really worth it to me, even if I am saving $80.
2) They are cramped and charge you like $40 for luggage check.
I have heard they are late often but have always been on time for me. I mean, it seems like most airlines run late these days.