The Advantage 21 SR 2007 vs Advantage 34 Party Cat TRX 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 Advantage 34 Party Cat TRX 2009 measures 34,0 feet overall (2009), giving it roughly 13,0 additional feet of deck space compared to the Advantage 21 SR 2007 at 21,0 feet (2007). Weight tells a clearer story for trailering families: the Advantage 21 SR 2007 tips the scales at 2 975 lbs — 2 967 lbs more than the Advantage 34 Party Cat TRX 2009 at 8 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 Advantage 34 Party Cat TRX 2009 is rated for 16 passengers, while the Advantage 21 SR 2007 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Advantage 34 Party Cat TRX 2009 could be the deciding factor.
Bottom line: Choose the Advantage 34 Party Cat TRX 2009 if your priority is putting more people on the water — it handles 16 passengers and at 34,0 ft it has the deck room to back that rating up comfortably. The Advantage 21 SR 2007 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.