The spec sheets list the Malibu Response LX 2012 as modified vee and the Malibu Response LXi 2008 as cut diamond, so check how each hull rides in the conditions you use before you decide.
On paper these two are close siblings in the size department - Malibu Response LX 2012 at 20,0 ft versus Malibu Response LXi 2008 at 20,0 ft. Weight tells a clearer story for trailering families: the Malibu Response LXi 2008 tips the scales at 2 800 lbs - 350 lbs less than the Malibu Response LX 2012 at 2 450 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.
The Malibu Response LXi 2008 tops out at 400 hp. Engine specs for the Malibu Response LX 2012 aren't listed - confirm with a dealer before selecting an outboard.Fuel capacity breaks the other way: the Malibu Response LXi 2008 carries 41 gallons versus 33 gallons in the Malibu Response LX 2012. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
Both boats are rated for 8 passengers - a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.
Bottom line: The Malibu Response LX 2012 and Malibu Response LXi 2008 are closely matched on the specs that matter most. Test-ride both on the water you actually use, check current dealer pricing, and factor in long-term service access before you sign.