Both the Crestliner C 1655 V 2008 and the Crestliner C 2070 V 2006 are modified-V designs, both built in aluminium, 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?
Size is the most obvious dividing line here. The Crestliner C 2070 V 2006 measures 20,0 feet overall (2006), giving it roughly 4,0 additional feet of deck space compared to the Crestliner C 1655 V 2008 at 16,0 feet (2008). At 775 lbs and 800 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 - 40 hp for the Crestliner C 1655 V 2008 and 60 hp for the Crestliner C 2070 V 2006. 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.
For family outings this is probably the sharpest distinction between the two. The Crestliner C 2070 V 2006 is rated for 8 passengers, while the Crestliner C 1655 V 2008 caps at 3. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Crestliner C 2070 V 2006 could be the deciding factor.
Bottom line: Choose the Crestliner C 2070 V 2006 if your priority is putting more people on the water - it handles 8 passengers and at 20,0 ft it has the deck room to back that rating up comfortably. The Crestliner C 1655 V 2008 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 3 that costs less to run day-to-day.