"I just went from a T3i to a 70D"
... and didn't upgrade your lens inventory? Although the 70D will be better in most cases compared to a Rebel T3i, it is the lens. It is always the lens.
EB
EOS 1D, EOS 1D MK IIn, EOS 1D MK III, EOS 1Ds MK III, EOS 1D MK IV and EOS 1DX and many lenses.
