Fry, in my experience, quite simply fish prefer dim lighting. I found fish to be nervous and jumpy with very bright lights and no plants, so since then I masked all my bulbs in tinfoil, so they were only emitting a small amount of light compared to before.
The fish were immediately more comfortable, and less jumpy, so since then I try to make the lighting as dim as possible.
My main tank has a few plants, but even with this dim lighting the plants are doing fine. I keep it on for around 12 hours. The tank gets a fair amount of sunlight, so that probably helps with the plants.
I dunno I guess my attitude is, I have a lot of love and respect for the fish, I would rather they were comfortable and the "viewability" was slightly comprimised, rather than the fish being uncomfortable and agitated.
Also personally, I like a dim look to a tank, looks more natural. When you go underwater in the sea or a river, things don't look so brightly illuminated as with a flourescent light.
Like steve 89's tanks for example, I like lighting like that.