Hi John
I sail out of Mystic, so it looks like you sail the same waters. I sail with a cruising club, with as many as thirty five to forty sailboats, so I have a good sense of how the 323 compares to others. First motoring: The 323 with the md11c and three bladed prop outperforms every other boat in the 30 -34 ft range, particularly in heavy seas. When you are slogging through Rhode Island Sound, powering through waves that are stopping 2 bladed boats in their tracks, you won't mind the drag on days with light wind. After all, this is a cruiser, and if your destination is Block, Nantucket, or Cutty, you want to get there. One other thing: as you already know you will see a lot of tidal current, and sometimes you will be in opposition. With a headwind and oncoming waves the 323 will maintain a minimum of 5 kts at 2000 rpm, which is 80% of max.
As for sailing, I have no problem staying with any of the other production boats of that era up to 34 ft. The only boat that gives me trouble upwind is a 34 Tartan who drafts over 9 ft with a centerboard. Yes, Catalinas have inboard jib tracks, but they need them because they are so beamy. All the other boats develop weather helm much sooner than a 323. However, in calm water under 5 kts you will get spanked. Then suddenly you remember "I'm not a racer, I'm a destination cruiser!" and you fire up the diesel. Also, in your sailing grounds a shoal keel is important. For instance, you could cut straight across the shoals between Edgartown and Nantucket while everyone else is making a long U through the channels.