The Custom Weld Sport - 17 ft. 2010 is a modified-V design and the Custom Weld X-Caliber 2013 is a tunnel hull 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 Custom Weld X-Caliber 2013 measures 21,0 feet overall (2013), giving it roughly 4,0 additional feet of deck space compared to the Custom Weld Sport - 17 ft. 2010 at 17,0 feet (2010). Weight tells a clearer story for trailering families: the Custom Weld X-Caliber 2013 tips the scales at 2 800 lbs - 1 700 lbs less than the Custom Weld Sport - 17 ft. 2010 at 1 100 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 Custom Weld X-Caliber 2013 is rated for 6 passengers, while the Custom Weld Sport - 17 ft. 2010 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Custom Weld X-Caliber 2013 could be the deciding factor.
Bottom line: Choose the Custom Weld X-Caliber 2013 if your priority is putting more people on the water - it handles 6 passengers and at 21,0 ft it has the deck room to back that rating up comfortably. The Custom Weld Sport - 17 ft. 2010 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.