I have Smarty on my commuter or Candy on my mountain bike. Not sure if it is real or perceived but I find the Smarty easier to disengage. Otherwise I find them to be exactly the same. DH bent a Smarty spindle, not sure if it is not as strong but it seems a little lighter weight than my Candy spindle.
Rails are pop on plastic colored things. Just for looks and customizing your smarty pedals.
Amanda
2011 Specialized Epic Comp 29er | Specialized Phenom | "Marie Laveau"
2007 Cannondale Synapse Carbon Road | Selle Italia Lady Gel Flow | "Miranda"
You don't have to be great to get started, but you do have to get started to be great. -Lee J. Colan