The Pro-Line 21 Sport 2007 vs Pro-Line 29 Super Sport 2009 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 29 Super Sport 2009 measures 28,0 feet overall (2009), giving it roughly 7,0 additional feet of deck space compared to the Pro-Line 21 Sport 2007 at 21,0 feet (2007). At 26 lbs and 53 lbs respectively, both sit in a similar weight class — either should pair comfortably with most mid-size SUVs and half-ton trucks, though always confirm your specific tow rating with the motor added.
The power gap is worth calling out. Rated to 600 hp, the Pro-Line 29 Super Sport 2009 has a 400-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 29 Super Sport 2009 carries 192 gallons versus 7 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 29 Super Sport 2009 is rated for 8 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 29 Super Sport 2009 could be the deciding factor.
Bottom line: Choose the Pro-Line 29 Super Sport 2009 if your priority is putting more people on the water — it handles 8 passengers and at 28,0 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.