Matching a modified vee Malibu Response LXi 2005 against a v25 diamond Malibu Sunscape 21 LSV 2008 means you're likely deciding between two genuinely different on-water experiences. Hull type shapes everything from ride quality and fuel burn to dock handling and resale trajectory.
Size is the most obvious dividing line here. The Malibu Sunscape 21 LSV 2008 measures 21,0 feet overall (2008), giving it roughly 19,0 additional feet of deck space compared to the Malibu Response LXi 2005 at 2,0 feet (2005). At 28 lbs and 35 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.
Both boats share a closely matched power ceiling — 400 hp for the Malibu Response LXi 2005 and 400 hp for the Malibu Sunscape 21 LSV 2008. Real-world performance will come down more to which motor is actually bolted on, its load at the time, and whether it's a 4-stroke or 2-stroke setup. Fuel capacity breaks the other way: the Malibu Sunscape 21 LSV 2008 carries 46 gallons versus 41 gallons in the Malibu Response LXi 2005. 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 Sunscape 21 LSV 2008 is rated for 12 passengers, while the Malibu Response LXi 2005 caps at 8. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Malibu Sunscape 21 LSV 2008 could be the deciding factor.
Bottom line: Choose the Malibu Sunscape 21 LSV 2008 if your priority is putting more people on the water — it handles 12 passengers and at 21,0 ft it has the deck room to back that rating up comfortably. The Malibu Response LXi 2005 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 8 that costs less to run day-to-day.