Conclusion: Overall, the CX-9 has just barely met my expectations. The poor sound quality and poor FM radio reception was certainly disappointing, but it has worked well enough when listening to the TV stations in the cardio workout area. Battery life has seemed reasonable to me and the unit has at least held up structurally after many hours of use.
Cons: I have not tracked exactly how long the CX-9 lasts on a pair of AAA batteries, but I would estimate that it will run for around 10-12 hours before needing to replace the batteries. This seems to be a reasonable amount of time, considering that I do not use the DBBS setting and am always within 10-15 feet of the FM transmitter source signal.