Pros: May not be the most neutral or most transparent but will be the most listened to.
Cons: Doesn't look as good as it sounds.
The HD 650s do just about everything right. Extremely forgiving yet detailed, it makes all music sound gorgeous. Absolutely dreamy, you'll find yourself lost within your music. Much of the sound attributes have been said before, e.g. the warmth and laid-back signature, so all I want to say is that if you ever had to buy a pair headphones solely for the enjoyment of music, pick the 650s. It's an absolute bargain at it's current price.
My only complaint is in aesthetics. If only it would look as beautiful and elegant as it sounds. Although, not really a complaint as the sound takes precedence and it's really not that ugly. Could use less plastic though.