When two boats share the same hull type — in this case both the Malibu Sunsetter 21 XTi 2005 and the Malibu Wakesetter 20 MXZ 2013 are modified vee designs with composite construction — the buying decision usually comes down to a handful of practical questions: how many people are you putting on the water, how far do you trailer, and what does your tow vehicle weigh?
Size is the most obvious dividing line here. The Malibu Sunsetter 21 XTi 2005 measures 21,0 feet overall (2005), giving it roughly 19,0 additional feet of deck space compared to the Malibu Wakesetter 20 MXZ 2013 at 2,0 feet (2013). At 33 lbs and 4 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 450 hp, the Malibu Wakesetter 20 MXZ 2013 has a 50-hp advantage over the Malibu Sunsetter 21 XTi 2005's 400-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Malibu Sunsetter 21 XTi 2005 carries 46 gallons versus 35 gallons in the Malibu Wakesetter 20 MXZ 2013. 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 Malibu Wakesetter 20 MXZ 2013 is rated for 13 passengers, while the Malibu Sunsetter 21 XTi 2005 caps at 12. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Malibu Wakesetter 20 MXZ 2013 could be the deciding factor.
Bottom line: Choose the Malibu Wakesetter 20 MXZ 2013 if your priority is putting more people on the water — it handles 13 passengers and at 2,0 ft it has the deck room to back that rating up comfortably. The Malibu Sunsetter 21 XTi 2005 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 12 that costs less to run day-to-day.