Both the Moomba Gravity XLV 2011 and the Moomba Outback 2009 are modified-V designs, both built in fibreglass, so 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?
On paper these two are close siblings in the size department - Moomba Gravity XLV 2011 at 23,0 ft versus Moomba Outback 2009 at 20,0 ft. Weight tells a clearer story for trailering families: the Moomba Gravity XLV 2011 tips the scales at 3 600 lbs - 850 lbs more than the Moomba Outback 2009 at 2 750 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 - 325 hp for the Moomba Gravity XLV 2011 and 325 hp for the Moomba Outback 2009. 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 Moomba Gravity XLV 2011 carries 50 gallons versus 28 gallons in the Moomba Outback 2009. 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 Moomba Gravity XLV 2011 is rated for 16 passengers, while the Moomba Outback 2009 caps at 10. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Moomba Gravity XLV 2011 could be the deciding factor.
Bottom line: Choose the Moomba Gravity XLV 2011 if your priority is putting more people on the water - it handles 16 passengers and at 23,0 ft it has the deck room to back that rating up comfortably. The Moomba Outback 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 10 that costs less to run day-to-day.