I don't get the love for flats either Geri. My 2007 Stingray wears nickel-rounds, all my P's wears nickle-rounds, cheap ones too, and none of them get changed very often. I haven't had flats on a bass since about 1978. I'm fairly certain that I'm too stupid to absorb the nuance that I'm missing out on, but I keep plugging away, oblivious to how badly I'm embarrassing the whole of bassdom.
On the topic of P vs. Stingray: IMO one can pull off any style with either. It's maybe easier to get an 80s funk tone out of a Stingray: It's a bigger, boink-ier more edgy tone. I suppose.
Yeah, at the moment, I don't have any material that I would think "gotta use the P on this" or "gotta use the Ray on that". The old Patrice Rushen tune "Forget me nots" (?) is proof that a P is great for funk material, too.
At the moment, all I can find in stock for strings my gauge are the Ernie Ball Power Slinkys (.050, .070, .085, .105, .135), a little heavier than usual. I can't see needing anything else and they last long enough.
As I said, by all means, play the strings that suit you (or the bass or the amp, or anything else in life that involves a choice). I would only ask that the same consideration is given to everyone's choices that I do (unless they are life-threatening, of course. Even then, there's a choice. AARRGGHHH!!!..
Carry on,
Geri O