I honestly feel like it depends on the skin. Some skins seem to attract terrible players. But then, some skins dominate. Frostfire Annie always wrecks my team when I play against one, while any Darius with a skin seem to be the only Darius' I can stomp in without picking Riven.
Yeah, I tend to play much more cautiously if the enemy team has skins then if they didn't. Something about it makes me wonder why people would spend money on a champ they don't play, and it makes me scared ;-;
"I just upgraded to Toasters 7." Lol ign: Darushiro