The solution is 60fps at 1/60s. Panning looks pretty natural again, as does most other motion, and you get clarity for fast-moving objects. You can play around with different framerates, but imo anything more than 1/120s (180 degree shutter in film speak) will start severely degrading the watch experience.
I've been doing a good bit of filming of cars at autocross and road course circuits the past two years, and I've received a number of compliments on the smoothness and clarity of the footage - "how does that video out of your dslr [note: it's a Lumix G9 mirrorless] look so good" is a common one. The answer is 60fps, 1/60s shutter, and lots of in-body and in-lens stabilization so my by-hand tracking shots aren't wildly swinging around. At 24/25/30fps everything either degrades into a blurry mess, or is too choppy to be enjoyable, but at 60fps and 1/500s or 1/1000s, it looks like a (crappy) video game.