Though my new 600D is not modded, for star clusters it should not be an impediment. I tested it on Omega centauri last night.
Attached are a full frame view and a rull resolution crop of the core.
Also a full frame and full res. image
here
Unfortunately the seeing wasnt 100%, but focussing with live view is much nicer than the old modded 350D, which is still the better camera for nebulae.
Scott