Would probably be useful to compare the spectral performance of the Baader UV/IR Cut filter as well, as that seems to be the default filter that imaging people go to after removing LP1 and LP2. Charts below.
For a comparison of the performance of the Canon 60D, 60Da, and a modded 550D, this article commissioned by Canon is a very good insight into the relativities of the three cameras. There is not much difference between the 60Da and the 550D but the edge goes to the 550D to my eyes.
http://www.astropix.com/HTML/I_ASTRO..._60D_550Da.HTM