I have been using this shower head for four months. As the previous reviewer mentioned, the water pressure is lower than most shower heads, even after I removed the flow regulator. There is still enough pressure to comfortably rinse my hair. Also, about 2 1/2 months into use all of the lights dimmed considerably - but a few weeks later, they intensified again, and have remained bright. Perhaps there was some variability with the water pressure in my house.
The shower light really is powered by the water flow, so I haven't had to worry about replacing batteries. The blue light is bright enough to shower with the lights off, and the red light is dimmer (but still looks cool). I have noticed that the light stays blue even with fairly warm water - it will not turn red until the shower is HOT. Interestingly, when the water temperature is borderline, both red and blue LEDs are lit, creating a neat purple effect.
Highly recommended for blue led lovers!