I have the Dreamer Design single and ditto. I haven't tried the ditto yet (due with 2nd in 2 weeks), but I love the single. I used it about 3x/week with my daughter prior to this pregnancy and it's been nothign but great. I'd read nothing but great reviews on it and it was highly rated by several sources. I got both of mine on ebay for about $80-$100 less than I saw anywhere else online, and that was new in box. It's definitely a mid-range jogger. It's not as expensive as a BOB utility stroller and the like, but it is more (and more substantial with better features) than InStep or those lower end brands. Ultimately, I'd definitely say the key is to get something with at least 16" wheels (smoother ride, better on terrain transitions). If I was more of a daily runner or ran longer distances (typically 3 mi is my distance), I'd probably have seriously considered 20" wheels.
People really like Baby Jogger brand strollers, from what I've heard/read. Also Kelty makes a good jogger, I believe. BOB Ironman is one of the top rated joggers, but it's about $100 more than the Dreamer Design.