I think it was great decision of the producers to choose Ant to replace Edd. After all these years, it was inevitable that the original duo would split. They evolve and doing the same thing for so long gets to be tiring after a while.
But in Ant, they found someone who already had a great track record, not only in automotive work but also in television presentation. So he doesn't need to try and be "the new Edd". He is simply doing the same thing he was on his own show, except in this new environment.
Usually these split ups end up with both sides greatly weakened by it. But I think in this case, it was a pretty successful evolution. And, as Edd said in his original "I'm outta here" video, if he goes ahead with his own plans, we may very well end up with two great show instead of one.