People talk about Nalbandian and Safin as some of the biggest wastes of talent, but Berdych is up there with them. When he's on it's a thing of beauty but his birdbrain is nearly unrivaled.
Nalbandian and Safin were able to keep it together far more often than Berdych, which allowed them to win Slams, TMC/TMS and have solid GS results. Berdych has one TMS title and a pretty horrid GS record so when you think of it, yes Nalbandian and Safin were bigger wastes of talent because they could have achieved even more than they already have.
Berdych was never going to amount to anything anyways, just a flash in the pan player hardly capable of keeping it together between the ears.