Now that I've had my 10" DOB for 4 months, I too have asked myself that same question about what to get next. After talking to the guys at the Pony Club observation night and reading various comments on this forum, I've decided that an ARGO is the next purchase I'm saving up for.
I've come to this conclusion based on the fact that I'm currently happy with the eye pieces I got with the DOB, and as a newbie under a dark sky I found it difficult to get my bearings. As time goes on, I'm sure I will learn the night sky, but right now I want to see as much as possible to keep my enthusiasm going.
Hope that helps.
