Both the Key West 1720 Pro 2009 and the Key West 1900 CC 2007 are modified-V designs, both built in fibreglass, 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 - Key West 1720 Pro 2009 at 17,0 ft versus Key West 1900 CC 2007 at 19,0 ft. Weight tells a clearer story for trailering families: the Key West 1900 CC 2007 tips the scales at 1 600 lbs - 450 lbs less than the Key West 1720 Pro 2009 at 1 150 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 150 hp, the Key West 1900 CC 2007 has a 30-hp advantage over the Key West 1720 Pro 2009's 120-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Key West 1900 CC 2007 carries 60 gallons versus 31 gallons in the Key West 1720 Pro 2009. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
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 Key West 1900 CC 2007 and its 150-hp ceiling. If fuel economy and quieter running matter more than top-end speed, the Key West 1720 Pro 2009 with its 120-hp rating is the more economical daily driver.