Both the Duckworth 23 2010 and the Duckworth Ultra Magnum Inboard 22 ft. 2008 are deep-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?
On paper these two are close siblings in the size department - Duckworth 23 2010 at 23,0 ft versus Duckworth Ultra Magnum Inboard 22 ft. 2008 at 22,0 ft. Weight tells a clearer story for trailering families: the Duckworth 23 2010 tips the scales at 3 610 lbs - 300 lbs more than the Duckworth Ultra Magnum Inboard 22 ft. 2008 at 3 310 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.
For family outings this is probably the sharpest distinction between the two. The Duckworth 23 2010 is rated for 7 passengers, while the Duckworth Ultra Magnum Inboard 22 ft. 2008 caps at 6. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Duckworth 23 2010 could be the deciding factor.
Bottom line: Choose the Duckworth 23 2010 if your priority is putting more people on the water - it handles 7 passengers and at 23,0 ft it has the deck room to back that rating up comfortably. The Duckworth Ultra Magnum Inboard 22 ft. 2008 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 6 that costs less to run day-to-day.