The SouthWind 201 FS 2012 is a tri-hull design and the SouthWind 210 SD 2008 is a modified-V 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 201 FS 2012 at 20,1 ft versus SouthWind 210 SD 2008 at 20,0 ft. Weight tells a clearer story for trailering families: the SouthWind 201 FS 2012 tips the scales at 4 400 lbs - 1 900 lbs more than the SouthWind 210 SD 2008 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 201 FS 2012 and 115 hp for the SouthWind 210 SD 2008. 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. Both carry nearly identical fuel loads - 50 gal and 50 gal - so range won't be a tiebreaker here.
For family outings this is probably the sharpest distinction between the two. The SouthWind 201 FS 2012 is rated for 10 passengers, while the SouthWind 210 SD 2008 caps at 9. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the SouthWind 201 FS 2012 could be the deciding factor.
Bottom line: Choose the SouthWind 201 FS 2012 if your priority is putting more people on the water - it handles 10 passengers and at 20,1 ft it has the deck room to back that rating up comfortably. The SouthWind 210 SD 2008 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 9 that costs less to run day-to-day.