What kind of indoors use? Any particular reason for wanting a SF?
- large area light?
- to look inside a computer case, under desks?
- for plumbing work?
- multiple brightness settings important?
- is size a concern?
and, no, I'm not trying to humor you, I'm trying to understand what your needs are. It's easy to say SF U2 (OK, not L-series), L4 or XZ2, but what's a good light for me may not be for your particular use.
I now have a U2, and am liking it more and more. Just last night I was looking for a small resistor behind/under my desk; with the U2 it was easy to change from the lowest setting to a brighter one instead of finding a brighter light - I also use it as a bike light.