The main reason for it, is the 20% atk speed reduction on ad carries and melee tanks, it gives him a much better chance at 1v1 scenarios and helps the team in team fights aswell. Plus you cant fault the 99 armor and 20% cd.

Frozen heart? Isn't that a massive waste of money considering you dont even use its 500 mana? Maybe a Randulins would be better, you can build it from a Gp5. I just dont think it is workth it for 20% CDR

I would be interested to hear your thoughts.