I received a review sample and put this through its paces right after I charged it. The first thing I noticed is the sound quality and the volume. My test music is Kind Of Blue because it has multiple instruments in the low, mid and high ranges. This speaker passed that test by allowing me to hear each instrument. I will say that the low end of the frequency range is a little thin. Not terrible, but I want to point that out.
For overall volume, this beats two other shower-type speakers I have tested in the past. The previous ones could not be heard clearly with water spraying and cascading in the background. This one can. It easily cut through the ambient shower noise and I was able to enjoy music in the shower.
The instructions consist of a single-sided sheet of paper that is clear and concise. Pairing this with my Samsung Galaxy Note 3 took seconds. Switching to FM radio is as simple as depressing and holding the On/Off button after you have turned the device on. I get poor reception no matter which radio I use in my area, but I did manage to find a clear station, so if you listen to FM radio that feature is as rock solid as the bluetooth speaker feature.
This is definitely waterproof. The power cable is a hybrid with a standard USB connector on one end and a tip type DC connector on the other. I tested it with a few wall chargers in the house and all work. The included cable is relatively sturdy, which is a plus given its non-standard configuration. Of course that configuration is one of the keys to ensuring that this speaker is waterproof.
Overall this is the best shower-style speaker that I have tested to date. The sound quality is a cut above most on the market, and the unit itself is perfect for listening anywhere. For example, the hanger hook would make this ideal for hanging off a rear view mirror in a car for hand's free calling, which this speaker also supports.