TForce changes suck for GP.
TForce tentatively no longer gives crit chance and gives 20% CDR as opposed 10%, as well as more atk spd. Zeal is no longer in the recipe; stinger is.
So, while this is great for Ezreal's who wanna build TF as opposed to IBG, it sucks for GP. Now, with TF, IE, and EReaver he only has 40% crit chance, or, with TF, IE, and a zeal item he has 50% crit chance with less AD.
Either way, he has less crit chance than the typical 60% build most people build on him, and in the second option his crits will also do less dmg. While he was OP for a long time, he has been balanced the last 2 or 3 months and this really hurts him.