I've rented from this place 3 or 4 times and I've never had a problem. I think their prices are very reasonable. Most recently I rented a piece of heavy equipment which malfunctioned after 2 hours of use, I returned the machine and they replaced it with a backup right away. I've had issues before and had to call for help, and most of the time they offered some helpful advice, or at least tried.
Based on reading some of the other reviews and my own experience it is obvious the equipment gets a lot of use, so I guess it would be a good idea to test it out thoroughly if possible before renting, or start using your rental during business hours in case there are issues.