John & Steve I thank you for your input regarding filters, though I do remain a bit confused. Whilst this thread was going, I had actually bought a UHC filter from doing previous research on it prior. Though not sure how it will go with my 6" dob. It arrived today, and when (if) the weather ever clears, I'll give it a run and see how it goes.
I did come across this article a few days ago, it's interesting reading on filters. It's written by David Knisley. Though the review only mentions the studies were done on apertures of 8" and up (so I don't know where I stand), but it makes note of exit pupil. It also lists which nebulas perform best for each filter. You guys will make more sense out of this article than I will as you'll are more experienced in this field.
http://pages.sbcglobal.net/raycash/filters.htm