Here's a pic of my 15/20mm setup with wider Hankooks. I drive mountain twisties all the time because I live so close to some great mountain roads in AZ. I have had no issues with damage and like the earlier poster, I do feel a slight positive difference in handling. For the money (approx. $260 for all four spacers) you can't beat it. Anyone on the fence - GO FOR IT!
AZ Roadster