If you are using for astroimaging it sure will be good for a long time. If you start chasing faint fuzzies visually you will be wanting more aperture sooner or later and the Dob is the most cost effective means get it. I am a visual observer and I made a jump from an 8inch Celestron Cat to a Discovery Dob of 15inches diameter. It is more troublesome to setup and transport but a big enough change upward in light gathering power to enable to see things which were previously invisible in the eight inch telescope. With your setup you can just take a longer exposure or stack short exposures to image fainter objects.
Have fun with your new scope, you can always post some of the images celestial you capture here.
Scotty