Both the Key West 197 SK 2012 and the Key West 218 SK 2011 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?
The power gap is worth calling out. Rated to 150 hp, the Key West 218 SK 2011 has a 35-hp advantage over the Key West 197 SK 2012'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 Key West 218 SK 2011 carries 30 gallons versus 19 gallons in the Key West 197 SK 2012. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
Bottom line: Performance buyers should lean toward the Key West 218 SK 2011 and its 150-hp ceiling. If fuel economy and quieter running matter more than top-end speed, the Key West 197 SK 2012 with its 115-hp rating is the more economical daily driver.