I recently purchased a used Marcus Miller S3 that had light guage flatwounds on it,..and I was quite impressed that it was actually more comfortable to play than with roundwounds. Tone really wasn't compromised when slapping at all.
Man I like this. Seriously. Call me crazy but I'm getting some jamerson vibe. I know he played a P bass... of course I know that. But the sound just has that warmth.