16s look better on a Combo than 15s, for sure. The only thing (for me) taking away from them is that the plastic's also a bit grey, competing with the wheel for the eye's attention (artyfarty ex-photographer speaking, but you did ask). I used CarPlan Original Black on mine, which is only £3.40 at my cash+carry but is surprisingly effective. Spray on and leave to dry, no buffing. Mine are just starting to return to grey which, after a whole Spanish summer on a 2002 ex-Menorca car, is doing well. Only slightly more expensive than a heat gun and a lot less than new arch trims. HST, I'd be quite keen on that body colour rear bumper for £20 I mentioned a while back (still not sold) to really make the grey wheels catch the eye.
If you just look at the side strips (I was getting rid of the bumper), CarPlan alone took them from this
to this