When two boats share the same hull type — in this case both the Key West 1720 CC 2007 and the Key West 198 SK 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 — Key West 1720 CC 2007 at 17,0 ft versus Key West 198 SK 2013 at 19,0 ft. At 115 lbs and 135 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.
Both boats share a closely matched power ceiling — 120 hp for the Key West 1720 CC 2007 and 140 hp for the Key West 198 SK 2013. 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. Fuel capacity breaks the other way: the Key West 1720 CC 2007 carries 31 gallons versus 3 gallons in the Key West 198 SK 2013. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
The Key West 1720 CC 2007 is rated for up to 5 people. Passenger data for the Key West 198 SK 2013 wasn't available.
Bottom line: Performance buyers should lean toward the Key West 198 SK 2013 and its 140-hp ceiling. If fuel economy and quieter running matter more than top-end speed, the Key West 1720 CC 2007 with its 120-hp rating is the more economical daily driver.