Personally I think its a tad unfair to both players to make any sort of comparisons as both were totally different types of players.I was fortunate to have seen King Colin from his first home game until his last and believe me I have never seen a City player like him and likewise the same must be said of David Silva,but for different reasons.
Colin had this set of powerful lungs which meant he could play with the same stamina after 90 minutes.He virtually had everything.Vision,passing,heading,tracking back,awareness.His only fault (if we want to be pedantic) was his tackling.
Fast forward to now and David Silva has the grace,technique,awareness,passing range,but for me his greatest asset is the ability to beat players with so much ease.
One comparison that should be made is their footballing manners which see`s both players being held in high esteem by virtually every fair minded football fan,irrespective of who they support.
I am so,so lucky to have witnessed two wonderful Sky Blue superstars at my Club.