I have the opportunity to sail both, the C250 and a late 80's C27. At first appearance the 250 seems like an impressive boat and has more modern lines... and yes, less teak. The C27 lines are definitely older and teak is apparent. More importantly if you look at the rigging of both boats, the C250 spars are, in my opinion considerably lighter, whereas the 27 has a very sturdy look about her mast and boom. There is also a large amount of freeboard on the 250 making it more prone to wind influence on the hull. At the marina where we rent these two boats, the C250 is affectionately named "Tubby".
After sailing her and sailing the C27.... "Ariel" the C250.. "Tubby" is very appropriately named. The C27 is a fine sailing boat and also very sought after especially with a well kept diesel.
Check out the link provided to the Catalina 27/270 website. I'm certain the folks there can also give you some great insight on the two boats. Happy Hunting!!
IC27/270A Website