The spec sheets list the Malibu Response LX 2008 as sv23 diamond and the Malibu Wakesetter 23 XTi 2006 as modified vee, 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 2008 at 20,0 ft versus Malibu Wakesetter 23 XTi 2006 at 23,0 ft. Weight tells a clearer story for trailering families: the Malibu Wakesetter 23 XTi 2006 tips the scales at 3 700 lbs - 1 250 lbs less than the Malibu Response LX 2008 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.
Both boats share a closely matched power ceiling - 400 hp for the Malibu Response LX 2008 and 400 hp for the Malibu Wakesetter 23 XTi 2006. 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 Wakesetter 23 XTi 2006 carries 47 gallons versus 35 gallons in the Malibu Response LX 2008. 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 23 XTi 2006 is rated for 14 passengers, while the Malibu Response LX 2008 caps at 8. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Malibu Wakesetter 23 XTi 2006 could be the deciding factor.
Bottom line: Choose the Malibu Wakesetter 23 XTi 2006 if your priority is putting more people on the water - it handles 14 passengers and at 23,0 ft it has the deck room to back that rating up comfortably. The Malibu Response LX 2008 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 8 that costs less to run day-to-day.