The Campion 650i BR 2009 is a modified-V design and the Campion Allante 645i SC 2013 is a deep-V 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.
On paper these two are close siblings in the size department - Campion 650i BR 2009 at 23,0 ft versus Campion Allante 645i SC 2013 at 25,1 ft. Weight tells a clearer story for trailering families: the Campion 650i BR 2009 tips the scales at 4 210 lbs - 173 lbs more than the Campion Allante 645i SC 2013 at 4 037 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.
Both boats share a closely matched power ceiling - 375 hp for the Campion 650i BR 2009 and 380 hp for the Campion Allante 645i SC 2013. 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. Both carry nearly identical fuel loads - 56 gal and 56 gal - so range won't be a tiebreaker here.
Both boats are rated for 9 passengers - a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.
Bottom line: The Campion Allante 645i SC 2013 at 25,1 ft is the right call if deck space, comfort, and entertaining are top of your list. The Campion 650i BR 2009 at 23,0 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.