Both the Champion Boats 187 CX 2006 and the Champion Boats 21 SX 2006 are modified-V designs, so 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 - Champion Boats 187 CX 2006 at 18,0 ft versus Champion Boats 21 SX 2006 at 20,0 ft. Weight tells a clearer story for trailering families: the Champion Boats 21 SX 2006 tips the scales at 1 650 lbs - 250 lbs less than the Champion Boats 187 CX 2006 at 1 400 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 200 hp, the Champion Boats 21 SX 2006 has a 50-hp advantage over the Champion Boats 187 CX 2006's 150-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Both carry nearly identical fuel loads - 48 gal and 50 gal - so range won't be a tiebreaker here.
Both boats are rated for 5 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.
Bottom line: Performance buyers should lean toward the Champion Boats 21 SX 2006 and its 200-hp ceiling. If fuel economy and quieter running matter more than top-end speed, the Champion Boats 187 CX 2006 with its 150-hp rating is the more economical daily driver.