Please post some pics when you have it all set up. I am keen to go to 15"s from 17"s, comfy ride is my goal. But the 17" alloys I have on look good and I don't remember seeing any pepperpots that stand out, or make the car shine.
Now's your chance to lure me to the small side.
If you've fitted spacers or nonstandard wheels, tell your insurers; it's a material change.