I spent about 50 non consecutive charter days on a 343 over the last four years and recently purchased an '06 model. I advise looking at the owner reviews in the specific owner review area of this site as well as the 343 owners yahoo group. There is also a good review posted in Practical Sailor archives if you have access to that site. Obviously I like this boat.
I like the manner in which it is rigged, that allows it to be single handed easily. With the sail configuration & shoal keel it is a bit tender; therefore, attention to sail trim & reefing beyond 15 knot air is a necessity. It is adequately powered with the Yanmar 3YM30; however, prop walk is pronounced with the fixed 3 blade fixed prop. My boat has a microwave in the galley and unfortunately it does consume another potential cabinet space in the galley. There isn't an abundance of storage in the galley; less than a Beneteau 331. The 343s also have an upright refrigerator instead of a top loading "ice box". There are pros & cons regarding each; however, you are going to need a fairly large house bank to run the refrigerator while away from the dock ---two 4Ds or a bank of golf cart batteries. I presently have 3 gp 31's AGM batteries (315 amps) and I will likely add a flexible solar panel later this year. The comfort level in the cabin is excellent---great headroom, lots of overhead natural lighting, and opening portlights / hatches for ventilation. I like the standard Lewmar ports, I know that I will be able to replace them in the future when the lenses craze without having to spend a fortune replacing the weird shaped fixed lenses on the newer boats. The head / shower is likely the largest on any boat in this size range. Full thickness matresses in the berth areas are also nice. The boat has a huge Stbd lazerette and port side storage area. As the previous post mentioned, Beneteau uses a brass hose barb on the shaft log to supply cooling water to the shaft while in operation; this is a maintenance item that should be checked on every haul out and replaced as necessary every 2-3 years. There have been some incidents in which corrosion has caused failure resulting in taking on water. ( could likely be due to excessive DC galvanic corrosion). In any event, have your surveyor knock on it and pull on the hose aggressively to test it while it is hauled out for the bottom inspection. On most production boats without dedicated seacocks, there are always mismatched threads from the thru hull fitting to the ball valves. On my next haul out I intend to install Groco flanged adaptors for the thru hull fittings and ball valves to eliminate the mismatched threads and will likely replace the ball valves at the same time. The ground tackle on my boat was undersized. I am presently replacing the 22 lb claw and 1/2 rode to a 33lb Lewmar claw, with 30' G4 3/8" chain, and 5/8" rode. Obviousy, I like this boat as a coastal cruiser. I like the lines and outside profile, the interior is comfortable and is well appointed, it sails well and is easy to handle. I have no regrets at this time; if the clock was reversed, I would buy her again. Good luck with your search.