When two boats share the same hull type — in this case both the Sundance NX21 2010 and the Sundance NX23 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 NX21 2010 at 21,1 ft versus Sundance NX23 2013 at 23,1 ft. Weight tells a clearer story for trailering families: the Sundance NX23 2013 tips the scales at 2 475 lbs — 2 290 lbs less than the Sundance NX21 2010 at 185 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.

The power gap is worth calling out. Rated to 250 hp, the Sundance NX23 2013 has a 135-hp advantage over the Sundance NX21 2010's 115-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 NX23 2013 carries 72 gallons versus 45 gallons in the Sundance NX21 2010. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.

Both boats are rated for 8 passengers — a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.