The 393 and the 411 production runs overlapped. The 411 began first, and ended about 2005, but continued as a Mooring charter badged boat. They are very similar, and the 2 cabin version is preferred, freeing up a large cockpit lazarette, and moving the galley where it belongs - mid ship. The forward head is one of the great aspects of these boats and I do not know why it is no longer built. It provides a great sail locker / feed location for a cruising A-sym. I can't stand to sleep in a V-berth, and so the pullman berth further aft is perfect. The difference in size is taken out of the main saloon, which is shorter in the 393. The later production runs tend to have the bugs worked out. As Paul notes, you want to examine each boat carefully. Shop very carefully for a surveyor, and check references.
The rigging is very robust, but have the attachments inspected carefully. B likes to use fender washer's in lieu of proper backing plates. It is a production boat after all, and all production boats balance cost against construction.
The deck cleats are installed on aluminum spacers through the toerail on a both boats, the aluminum corrodes, swells, and splits the rail. Plan on getting rid of those aluminum spacers, and replace them with something like SS.
For a number of years B installed deadlights in the cabin roof of their boats, and the 393 continued that tradition. They are placed where they commonly get walked on as crew work at the mast, and they will inevitably begin leaking. I prefer traditional cabin top hatches, which are easily maintained.
Inspect the teak inlay on the cockpit seating and swim platform. Many of the older boats will show signs of delamination here. These are teak veneer over plywood, and can be very pricy to repair / replace.
Finally, consider having an ABYC electrician independently inspect your electrical system prior to final sale, should you get serious about any particular boat. I see many, incompetent DIY electrical installations on boats. For some reason, many boater's fancy themselves capable of wiring a boat. Repairs to DIY electrical work can get very expensive.
Both boats sail very nicely, in fact the biggest difference is between the full-batten "classic" rig, and the roller-furlers. Give me a classic rig 393 and I can sail to wind ahead of any roller-furler 411.