When two boats share the same hull type — in this case both the Weld-Craft 1648 Camo Duck Boat 2011 and the Weld-Craft RS 70 (20 ft.) 2010 are flat designs with aluminum 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?
Both boats share a closely matched power ceiling — 35 hp for the Weld-Craft 1648 Camo Duck Boat 2011 and 40 hp for the Weld-Craft RS 70 (20 ft.) 2010. 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.
Bottom line: The Weld-Craft 1648 Camo Duck Boat 2011 at 16,0 ft is the right call if deck space, comfort, and entertaining are top of your list. The Weld-Craft RS 70 (20 ft.) 2010 at 2,0 ft wins on trailering ease, likely lower purchase price, and simpler docking — a solid choice for a buyer who wants more boat for less money.