Don't know much about the 265 Express or the Chesapeake. Have owned the 30' Marlin and presently own the 305 Express. So I can give an opinion on those models.
The hull is the same and the ride was the same to me for both boats. Marlin pros for me were the cockpit is about 12 square feet larger than the Express, you have a walk around. Cons of the Marlin for me and the first one was huge, no easy access to the generator compartment (every time you needed to do anything in there which was frequent you had to remove screws and caulk), smaller cabin area due to the walk around and less helm seating.
Express pros for me are larger cabin area and bathroom, nice clean access to the generator compartment, taller front window which eliminated me looking through the top of it, electronics compartment, center helm with great visibility and better helm seating and larger fish box. My family and friends really like the seating arrangement much better than on my Marlin. The biggest con for me on the Express is the center helm and captains seat does make for tight access to the cabin etc. However, I've learned to turn the seat and things work fine. I also miss the extra 12 square feet of cockpit space.
I really liked both boats and frankly would have probably never sold the Marlin if it wasn't for the generator access and poor to me helm seating.They're both great boats. You just need to decide what features will make you the most happy. Good luck in your decision.