The Crestliner CR 1648M 2010 is a flat-bottom design and the Crestliner Sport Classic 2085 2008 is a pontoon 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.
Size is the most obvious dividing line here. The Crestliner Sport Classic 2085 2008 measures 20,0 feet overall (2008), giving it roughly 4,2 additional feet of deck space compared to the Crestliner CR 1648M 2010 at 15,8 feet (2010). Weight tells a clearer story for trailering families: the Crestliner Sport Classic 2085 2008 tips the scales at 1 900 lbs - 1 480 lbs less than the Crestliner CR 1648M 2010 at 420 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 90 hp, the Crestliner Sport Classic 2085 2008 has a 55-hp advantage over the Crestliner CR 1648M 2010's 35-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load.
For family outings this is probably the sharpest distinction between the two. The Crestliner Sport Classic 2085 2008 is rated for 9 passengers, while the Crestliner CR 1648M 2010 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Crestliner Sport Classic 2085 2008 could be the deciding factor.
Bottom line: Choose the Crestliner Sport Classic 2085 2008 if your priority is putting more people on the water - it handles 9 passengers and at 20,0 ft it has the deck room to back that rating up comfortably. The Crestliner CR 1648M 2010 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 4 that costs less to run day-to-day.