The Pro-Line 21 Sport 2007 vs Pro-Line 35 Express 2008 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 Pro-Line 35 Express 2008 measures 35,0 feet overall (2008), giving it roughly 14,0 additional feet of deck space compared to the Pro-Line 21 Sport 2007 at 21,0 feet (2007). Weight tells a clearer story for trailering families: the Pro-Line 35 Express 2008 tips the scales at 11 200 lbs - 8 600 lbs less than the Pro-Line 21 Sport 2007 at 2 600 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 900 hp, the Pro-Line 35 Express 2008 has a 700-hp advantage over the Pro-Line 21 Sport 2007's 200-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Pro-Line 35 Express 2008 carries 320 gallons versus 70 gallons in the Pro-Line 21 Sport 2007. 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 Pro-Line 35 Express 2008 is rated for 10 passengers, while the Pro-Line 21 Sport 2007 caps at 6. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Pro-Line 35 Express 2008 could be the deciding factor.
Bottom line: Choose the Pro-Line 35 Express 2008 if your priority is putting more people on the water - it handles 10 passengers and at 35,0 ft it has the deck room to back that rating up comfortably. The Pro-Line 21 Sport 2007 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 6 that costs less to run day-to-day.