I use an unmodded DSLR and find I get far better pics using a light pollution filter. The camera also seems to "wake up" in Ha.
There's a Plethora of filters out there with multi channel band pass for single shot colour, from something like the wide band Baader Moon and skyglow, to the relativity narrow band Astronomic UHC and everything in between like the CLS and Lumicon Deep Sky. The narrower multi-band filters tend to make the colour go a bit funky, but the contrast boost is often worth it.
In my experience no amount of stretching will equal the contrast gained with the correct filter for the job.
Bintel have very useful spectrum graphs along with their Astronomic filters that show what they pass and what they don't. This is also a good page for comparisons.
http://www.astrosurf.com/buil/filters/curves.htm
Keep in mind the more narrow filters require longer exposure.
I shoot just about everything now with filters, except comets. Some comets have spectral emissions in the light pollution bands which a filter would attenuate.
M8 and M20 with a Lumicon Deep Sky filter. M42 with some subs using Lumicon Deep Sky and a different stack of subs using a Baader Semi-Apo filter, same for the Horsehead.
M42, because it's so bright shoots pretty well without any filter, but IC434 really benefits.