The Campion Allante 645i SC 2011 vs Campion S 505i BR 2005 comparison sits squarely in the category of decisions where specs alone won't tell the whole story — intended use, storage, and long-term ownership costs all factor in.
Size is the most obvious dividing line here. The Campion Allante 645i SC 2011 measures 23,1 feet overall (2011), giving it roughly 7,1 additional feet of deck space compared to the Campion S 505i BR 2005 at 16,0 feet (2005). Weight tells a clearer story for trailering families: the Campion Allante 645i SC 2011 tips the scales at 4 037 lbs — 2 063 lbs more than the Campion S 505i BR 2005 at 1 974 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.
The power gap is worth calling out. Rated to 320 hp, the Campion Allante 645i SC 2011 has a 185-hp advantage over the Campion S 505i BR 2005's 135-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Campion Allante 645i SC 2011 carries 56 gallons versus 19 gallons in the Campion S 505i BR 2005. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
For family outings this is probably the sharpest distinction between the two. The Campion Allante 645i SC 2011 is rated for 9 passengers, while the Campion S 505i BR 2005 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Campion Allante 645i SC 2011 could be the deciding factor.
Bottom line: Choose the Campion Allante 645i SC 2011 if your priority is putting more people on the water — it handles 9 passengers and at 23,1 ft it has the deck room to back that rating up comfortably. The Campion S 505i BR 2005 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.