Both the Triton Boats 18XS 2012 and the Triton Boats 2070 SC 2009 are modified-V designs, the first built in fibreglass and the second in aluminium, 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 - Triton Boats 18XS 2012 at 18,7 ft versus Triton Boats 2070 SC 2009 at 20,0 ft. Weight tells a clearer story for trailering families: the Triton Boats 18XS 2012 tips the scales at 1 690 lbs - 565 lbs more than the Triton Boats 2070 SC 2009 at 1 125 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 - 135 hp for the Triton Boats 18XS 2012 and 115 hp for the Triton Boats 2070 SC 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.
For family outings this is probably the sharpest distinction between the two. The Triton Boats 18XS 2012 is rated for 600 passengers, while the Triton Boats 2070 SC 2009 caps at 6. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Triton Boats 18XS 2012 could be the deciding factor.
Bottom line: Choose the Triton Boats 18XS 2012 if your priority is putting more people on the water - it handles 600 passengers and at 18,7 ft it has the deck room to back that rating up comfortably. The Triton Boats 2070 SC 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 6 that costs less to run day-to-day.