Pros
Discovering parts of Las Vegas I wouldn't normally visit. Meeting nice people from all over the Valley and the world.
Cons
With the price of gas right now, my pay for using a mid-sized vehicle averaged out to $8 per hour (before taxes), even after 3 "bonuses." This is less than the Nevada minimum wage of $12. Regardless of what the app tells you, Lyft takes about 2/3 of the earnings for each ride, charging both for the rental and extra fees they claim have to do with the cost of car maintenance. Not sure why maintenance and everyday wear wouldn't be handled by Hertz as a normal part of their fleet ownership, as it would with any other rental. Indeed, if you're doing the Express Driver program, you have to take the car for service after getting a voucher from Hertz.
On a different note, the number of riders with no picture or fake names is really high in Las Vegas compared to other places where I've driven. This issue has become a safety concern.