Hi Meru,
Nice work, that's a winning combination in terms of equipment, so should only get better. As H suggested, just increase the contrast a bit more. Will add depth. can you post the O3 sub and Ha subs as well.
I like the NGC3603 and NGC253 best. lots of detail in 253.
I like 3603 nebula because the HaRGB editions resemble the bell jar with the rose in beauty and the beast with a glowing rose. so i like to call it the B&B nebula. Could just be my imagination.
http://www.docdb.net/img/dso/ngc/3/n...p_1-dieter.jpg
http://apod.nasa.gov/apod/image/0803...00crawford.jpg
http://cdn.astrobin.com/images/d1dfc...b5_resized.jpg
Alistair