I assume the 43 you're referring to is the newer model, which we have a 2008. Funny but a friend has an 04 423 and we raft up together and do comparisions on the two models. I'll do my best to share the differences as I see them. The 43 has a 13.5' beam which is carried well aft. It's what gives the boat a roomy feel both in the cockpit and down below. On deck the 43 has twin wheels and a huge cockpit. The 423 has a smaller cockpit and less seating area. We spend a lot of time topside so we love the extra room. Down below the 423 does have the darker more traditional look. It's warm and cozy. The nav table is dedicated where the 43 you sit on the end of the port salon seat. If you use the nav table the 423 wins. If not then the 43 does with the extra cushion length. The 43 has lighter colored wood. Ours is two toned with the majority of the wood in a light color and the trim in the darker wood. Definately more modern/euro looking than the 423. Something you either you like or don't. The 43 salon is squared off vs the rounded style of the 423. I think the 43 has a more airy open feel down below. Some of this may be impacted by the eyebrow ports. The galley in the 423 is to STBD and the 43's is to Port, both tucked in next the companion way. The 43's fridge is manufactured unit where the 423's is built in by Beneteau. The 43 has separate compressors for the fridge and freezer. I believe, but wont swear to it, the 423 has a single compressor which should equate to less power consumption when on the hook. I think the galley in the 43 may have a tad more storage. Both boats have two heads and cabins. The 43 has a separate shower area in the aft head. The 423 has much nicer forward cabin with lots of nice wood. It's the one draw back of the 43 and still something I wish was different. Decorating helps but only to a certain degree. I think the 43's salon is a bit roomier, especially at the base of the companion way. Both boats have numerous hatches and ports for great ventilation. As I mentioned before the 43 has the long cabin windows. The 43 has built in hatch screens and shades. Pull one direction and you have shade. Pull the other and you have screens. Pull them apart and you have free flowing light and air. B did a very nice job on them. Access to water heater, pumps, valves is about the same on both boats. I know the 43 has the thruhulls tagged with their functional names. The DC panel on the 423 has breakers for most every function. The 43's are grouped resulting in far fewer switches. I thought it would be an issue but in fact so far it's not been. Back up on deck the 423 has a full rig where the 43's is a 9/10ths fractional. The 43's mast air draft is 60', not counting the windex, wind instruments, antenna, etc. Still very ICW friendly. I believe the 423's air draft to be 58'. The 423 has a double anchor roller versus the 43's single. Not an issue so far since I keep a Fortress as a backup anchor. The 43 has a fairly flat hull shape where the 423 is more rounded. IMO the 43 is the faster of the two boats. Keep her flat with no more than 10-5 degrees of heel and she'll fly. Hard on the wind (15kts give or take a bit) I've seen speed thru the water of 8.5 to 9.0kts. With wind on the beam it jumps to 9.0 to 9.5, even touching 10 in the puffs. Both boats will handle the heavy chop the Chesapeake throws at you. We made the run from Cape May NJ to Baltimore this summer and ran up Delaware Bay in 20-25kt following winds and seas 5-7'. We were motor sailing at apx 2200 rpms with the main partially set and full head sail. The main's outhaul car had an issue or we'd had run 100% sail. We averaged slightly better than 8kts and the boat handled like a dream. I cant say enough on how pleased I am with her performance. Not to mention her good looks. We get a lot of compliments on her lines. Well that's the highlights. Let me know if you have any questions.
Mike