I tend to be very picky when it comes to exercise. Iv'e worked out at a great many places over the years, and I want workouts that are designed to produce serious results
I would recommend RiPT Fitness and its crew in a heartbeat. I know that my own sprinting abilities and general athletic prowess have improved in part due to their workouts. I especially like their Woodway treadmills, since they are easy on the joints and (being non-motorized) are especially useful for hard interval training, including the occasional brief bust of all-out sprinting. I would go there a lot more often if I could.