To be honest with you, a 10" will give you unreal views as they are, and it would take you a good year or maybe more to actually pick differences within the scopes. If you where talking the difference between say a 16" and a 10" then you would be able to see some differences from the start.
Learning to view though a telescope is a art, one that can be learnt and isn't super difficult but there are techniques to viewing. So if it where me, i would go the 10" for now, and if you decide that you can handle and would like more aperture you can resell the 10" as they generally hold their value quite well and up size.
Just for example i can see M83 with details, Centuras A with details even to the dark sash across the front, i can see the bits in there. You can see the bubble on Eta carina, crab nebula, tarantula neb, M42 + running man and a score of other extended nebs. Ive viewed 89 of the possible 104 messier objects, seen the flame nebula that sits beside the horse head and i am not sure if i saw the horse head, but.... yeah i thought i just made it out. I used a Meade series 5000 20mm super plossel ep (not expensive and not absolutely brilliant but nice approx $129 from bintel) with a bintel 2" 2x ED barlow and my 10" to do all of these objects. hope that helps
