When my wife showers, she always has the lights on. When I shower, I'm either/or.

I have a large walk-in shower with no door, so there is ambient light in the shower. Good enough for me during the day, but at night or early morning, I'll use the light. I have four lights in my shower.

If I had a shower curtain, or a shower door, even if it was clear glass, I'd want lighting. Actually I think I'd ALWAYS want lighting. I may not use it, but I'd want the option.

A air tight IC can will run you $10. A trim kit anywhere from $25-$50. If you're having a fan in the shower, which you should, the electrician is already running wire to the fan. He can just run 12-3 instead of 12-2 and you can run the other hot to the light.

Or if you're really wary about having that extra fixture, just install a fan/light combo with 12-3 wiring. That will enable you to run the light off one switch and the fan off another.

Ok! Thanks for the feedback! That's exactly what I needed to know. :c)