When two boats share the same hull type — in this case both the Sundance FX19 Vapor 2012 and the Sundance SV21 2013 are modified vee designs with fiberglass construction — the buying decision usually comes down to a handful of practical questions: how many people are you putting on the water, how far do you trailer, and what does your tow vehicle weigh?
On paper these two are close siblings in the size department — Sundance FX19 Vapor 2012 at 19,1 ft versus Sundance SV21 2013 at 20,6 ft. At 102 lbs and 185 lbs respectively, both sit in a similar weight class — either should pair comfortably with most mid-size SUVs and half-ton trucks, though always confirm your specific tow rating with the motor added.
The power gap is worth calling out. Rated to 200 hp, the Sundance SV21 2013 has a 50-hp advantage over the Sundance FX19 Vapor 2012's 150-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Sundance SV21 2013 carries 45 gallons versus 31 gallons in the Sundance FX19 Vapor 2012. 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 Sundance SV21 2013 is rated for 6 passengers, while the Sundance FX19 Vapor 2012 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Sundance SV21 2013 could be the deciding factor.
Bottom line: Choose the Sundance SV21 2013 if your priority is putting more people on the water — it handles 6 passengers and at 20,6 ft it has the deck room to back that rating up comfortably. The Sundance FX19 Vapor 2012 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 4 that costs less to run day-to-day.