My experience is that it's a very small difference. I've used (and made) packs with solid fabric, with mesh over reticulated fiber, and also external frames with mesh backbands. My shirt is wet from sweat no matter what. Yes, I'm very slightly warmer with the solid fabric, but it's hardly noticeable, and to me it isn't worth the extra weight.
As to pack movement, I have experienced no difference at all in that regard. I suppose with a very smooth fabric there might be a difference compared to mesh, but my packs with solid fabric all use 160d or 330d cordura, which has some grip to it.