I have had my sewing room in the basement for probably 6 or 8 years now. I love it! Concrete floor means it is easy to sweep up all the thread and fabric snips. Lots of fluorescent lighting. Lots of space. I don't have any natural light, so if I want to match colors I run upstairs or use an Ott light. I do run a dehumidifier but it doesn't do much condensing since it is so dry naturally. I find I get cold more in the spring and fall when the central heat isn't running much, so I have a space heater I turn on when I need to.
I'm looking at moving soon, and I may actually have to use a bedroom for my studio. I am definitely not looking forward to carpeting!