Go with the 473. First and foremost, if you plan to live aboard and cruise for a while, you will be very happy for the extra room. I'm not aware of anyone cruising on a boat and thinking that they have too much room and wish they went with a smaller boat. Likewise, the larger cockpit on the 473 will be material to your enjoyment once you're on the hook and settled in, particularly if you're the type that likes to host social gathering. Particularly considering your comment that you may look to move up in a couple of years, you'll be wasting money going with the smaller boat, and you'll be thinking fairly frequently that you wish you had the room of the 473. Just MHO.
Also, the 473 is known to have a more seakindly motion. I don't know this from personal experience, but have discussed it with actual owners and a dealer. The 423 apparently pounds fairly easily, and the 473 does not pound much at all. Boats that pound too easily can be very uncomfortable in snotty conditions.
As to the posters that say the 423 is a better looking boat, I'm not sure I see that. Obviously that kind of thing is incredibly subjective, but the 473 and the 423 have very similar lines. The 473 is just larger. I actually think they both are attractive boats.
A note about the Catalina 470, which I think got mentioned. It is a very nice boat, but I think it has a pullman berth arrangement up forward. That's the kind of thing that either you like it or you don't. We had that once on our Bayfield 36, and we won't do it again. It's a pain for one person to have to climb over the other, either to get in or out. Climbing all over each other sounds fun, but after the first 27 times, it gets real old real fast.
Good luck with your choice. In the end, you'll enjoy either one, so don't sweat it too much (and if you buy the 423 I bet you'll end up enjoying them both eventually.
