I loved them! I just wanted more capability from my ST so I lifted it back to stock height and put the stock wheels back on with new tires. I definitely enjoyed it being lowered with the 18's! I currently have Cooper ATR's on my stock wheels. I have my 18" wheels and 18" tires. I personally would not go bigger than 18". They have a great look and give a smoother ride due to more air and rubber compared to 20" or 22" wheels/tires.
-Gary