The Crestliner CR 1648 2010 is a flat-bottom design and the Crestliner Sportsman 14 SS 2007 is a modified-V design, so you're likely deciding between two noticeably different on-water experiences. Hull type shapes everything from ride quality and fuel burn to dock handling and resale trajectory.
On paper these two are close siblings in the size department - Crestliner CR 1648 2010 at 15,8 ft versus Crestliner Sportsman 14 SS 2007 at 14,0 ft. At 420 lbs and 520 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 - 35 hp for the Crestliner CR 1648 2010 and 35 hp for the Crestliner Sportsman 14 SS 2007. 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.
Both boats are rated for 4 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.
At this size, power-to-weight ratio matters more than outright horsepower. The Crestliner CR 1648 2010 comes in at 12 lbs per hp versus 15 lbs per hp for the Crestliner Sportsman 14 SS 2007. The lower the ratio the more explosive the acceleration - meaningful on a short RIB where bursts of speed, quick planing, and agility in surf or tight waterways define the experience.
Bottom line: The Crestliner CR 1648 2010 and Crestliner Sportsman 14 SS 2007 are closely matched on the specs that matter most. Test-ride both on the water you actually use, check current dealer pricing, and factor in long-term service access before you sign.