The SouthWind 212 SD 2010 is a modified-V design and the SouthWind 229 FS 2010 is a tri-hull design, so you're likely deciding between two noticeably different on-water experiences. Hull type shapes everything from ride quality and fuel burn to dock handling and resale trajectory.
On paper these two are close siblings in the size department - SouthWind 212 SD 2010 at 20,5 ft versus SouthWind 229 FS 2010 at 22,8 ft. Weight tells a clearer story for trailering families: the SouthWind 229 FS 2010 tips the scales at 3 500 lbs - 1 000 lbs less than the SouthWind 212 SD 2010 at 2 500 lbs. That difference is meaningful if you're working within a half-ton or three-quarter-ton truck's tow rating, especially once you factor in a motor, gear, and fuel.
Both boats share a closely matched power ceiling - 115 hp for the SouthWind 212 SD 2010 and 115 hp for the SouthWind 229 FS 2010. Real-world performance will come down more to which motor is actually bolted on, its load at the time, and whether it's a 4-stroke or 2-stroke setup. Fuel capacity breaks the other way: the SouthWind 212 SD 2010 carries 50 gallons versus 35 gallons in the SouthWind 229 FS 2010. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
For family outings this is probably the sharpest distinction between the two. The SouthWind 229 FS 2010 is rated for 11 passengers, while the SouthWind 212 SD 2010 caps at 10. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the SouthWind 229 FS 2010 could be the deciding factor.
Bottom line: Choose the SouthWind 229 FS 2010 if your priority is putting more people on the water - it handles 11 passengers and at 22,8 ft it has the deck room to back that rating up comfortably. The SouthWind 212 SD 2010 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 10 that costs less to run day-to-day.