hi chris,
this is actually a tougher subject than most people think. the dynamic range of the tarantula is pretty extreme. and actually when using an unmodified dslr on the tarantula it is actually difficult to get much colour at all in fact very little red and some green if stretched a lot. I think you are comparing your shots to modified dslrs.
so if there is any improvement I would consider modding the camera to allow more Ha onto the sensor. perhaps try to shoot some galaxies /globs or planetary nebs where the Ha is less important and you'll be able to compare your images more closely and will then notice that your results are consistent with un modded dslrs. (although Justin Tilbrook is the king of the unmodded dslr somehow he manages some fancy processing to punch out some more red).
cheers
russ
edit: check out Justin's tarantula
http://www.iceinspace.com.au/forum/s...d.php?t=131302 notice the green.