Has anybody used ball joints all around on a road car?
Is the ride a lot different from Poly bushes?

Do you mean Rose Joints?

Certainly do.

I haven't myself, but if/when my poly bushes die i might modify my wishbones. to fully rose jointed and get the alignment properly set up

Yes. I have full rear rosejoint setup and top fronts joints

Don’t really notice any difference tbh. In ride quality