How reliable is DFT? Front cover of Organic and Biomolecular Chemistry

The front cover of Organic & Biomolecular Chemistry, Issue 3, 2011 highlights:

How reliable are DFT transition structures? Comparison of GGA, hybrid-meta-GGA and meta-GGA functionals
L. Simon and J. M. Goodman Org. Biomol. Chem. 2011, 9, 689-700.
DOI: 10.1039/C0OB00477D