not all that familiar with c-dory (an aquaintance in San Diego had a 22 he used for fishing). fast and about the same room as the R-21EC. Very well built from what I saw. easy to trailer I hear.
Nimble...I looked at pretty closely before I bought the Ranger. same speed as the Ranger but 18" wider and 3 feet longer with a LOT of room inside but not much useable space outside The front cockpit is mainly good for anchor handling and uncomfortable for riding in, while the rear cockpit is a bit roomier (room for 2), the big "box" over the engine gets in the way. flat bottom really pounds in any kind of chop and handling is a little squirrelly. uses 4x more fuel (gas). outboard is better for reverse handling but you may want to re-power if the engine has over 1000 hours. The green hulled boats are a nightmare to keep looking nice. Draft is about the same but trailering is more work and needs a larger tow vehicle.
There is a nice one listed on BoatUs's site, its located near you (don't know if it's still avail though)http://www.boatus.com/classifiedads/searchDetails.aspx?action=search&adkey=66830. It can be a lot of work keeping up with the complex "live aboard" systems that are 10- 20 years old and no factory help available . The boats were very well built but they have cored hulls that may start to give expensive trouble.
Ranger 21...I bought one
Mainly its a questiom of fast or slow...spending 2 weeks aboard or a weekend...wanting to spend all your time at the wheel and inside or fishing /swimming/enjoying some sun...Cost of operation(mainly fuel) and hassle involved to use the boat. and of course the use/fix ratio.
How "little" the co-pilot is has a bearing to I suppose. My wife and I both fit in the R-21. But my cousin "little" Gary is 6"6" and 325 lbs...you'd have to grease him up to fit into the pilothouse with me (no thanks)