On our Vegas trip, we selected Firefly for out rental car due to price. When we arrived in Vegas, went to the Firefly counter, there was a line. A line that was not moving. The counter agents weren't helping anyone either. So we waited. Finally, the line became a little unruly and demanded to know what the issue was....No Cars!? Whaaaaat? Yep, no cars. There was a convention and Firefly was out of cars! Isn't Vegas a convention town? They overbooked and we got screwed!
The line dispersed to other companies. We found a nice car at a reasonable price at another National-ly known rent a car company. Not at a super cheap price but they had cars.
Your in Vegas...if you want to take a long shot, rent from Firefly. For me, I'll risk my $$ at the casinos where at least I know my odds!