What kind of 34 footer? Most modern 34s (say Catalina) will out-maneuver the BC cutter by a huge amount. It'll be like getting out of a 67 Pontiac wagon and into a GoKart.
If you're thinking of another full keel/heavy displacement 34 footer, then you've got more momentum, and probably/possibly no improvment in close quarters maneuverability, just a heavier similar boat.
If indeed you are going to a more modern design you will be amazed at the difference, esp in reverse.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)