Even though I have been imaging for years, I've had no experience with colour imaging using Ha luminance until recently.
The processing technique of blending Ha/R at around 80%/20% for both luminance and the R-channel seems to sacrifice a bit of detail when compared to the Ha luminance.
Here is an experiment where a 100% Ha luminance has been combined with the RGB image. While it has a characteristic salmon colour in the fainter regions, I believe this can be overcome by increasing the RGB exposures. Otherwise it doesn't have the pure white stars and overall salmon colour appearance that is usually associated with using a straight Ha luminance.
http://users.westconnect.com.au/~sja...c7293newc.html
It is still a work in progress.
Regards
Steven