The Donzi 26 ZF 2006 vs Donzi Z-21 1987 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.
The power gap is worth calling out. Rated to 400 hp, the Donzi 26 ZF 2006 has a 50-hp advantage over the Donzi Z-21 1987's 350-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Donzi 26 ZF 2006 carries 180 gallons versus 66 gallons in the Donzi Z-21 1987. 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 Donzi 26 ZF 2006 is rated for 7 passengers, while the Donzi Z-21 1987 caps at 6. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Donzi 26 ZF 2006 could be the deciding factor.
Bottom line: Choose the Donzi 26 ZF 2006 if your priority is putting more people on the water - it handles 7 passengers and at 26,0 ft it has the deck room to back that rating up comfortably. The Donzi Z-21 1987 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 6 that costs less to run day-to-day.