The Xpress H18SS 2011 is a modified-V design and the Xpress Yukon 18 2010 is a deep-V design, so you're likely deciding between two noticeably different on-water experiences. Hull type shapes everything from ride quality and fuel burn to dock handling and resale trajectory.
On paper these two are close siblings in the size department - Xpress H18SS 2011 at 18,0 ft versus Xpress Yukon 18 2010 at 18,0 ft. At 1 290 lbs and 1 215 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.
The power gap is worth calling out. Rated to 150 hp, the Xpress H18SS 2011 has a 35-hp advantage over the Xpress Yukon 18 2010's 115-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Both carry nearly identical fuel loads - 30 gal and 30 gal - so range won't be a tiebreaker here.
For family outings this is probably the sharpest distinction between the two. The Xpress Yukon 18 2010 is rated for 5 passengers, while the Xpress H18SS 2011 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Xpress Yukon 18 2010 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Xpress H18SS 2011 comes in at 9 lbs per hp versus 11 lbs per hp for the Xpress Yukon 18 2010. The lower the ratio the more explosive the acceleration - meaningful on a short RIB where bursts of speed, quick planing, and agility in surf or tight waterways define the experience.
Bottom line: Choose the Xpress Yukon 18 2010 if your priority is putting more people on the water - it handles 5 passengers and at 18,0 ft it has the deck room to back that rating up comfortably. The Xpress H18SS 2011 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 4 that costs less to run day-to-day.