The Xpress HD17 2011 is a flat-bottom design and the Xpress SV16CC 2009 is a modified-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.
The Xpress SV16CC 2009 tops out at 60 hp. Engine specs for the Xpress HD17 2011 aren't listed - confirm with a dealer before selecting an outboard.
For family outings this is probably the sharpest distinction between the two. The Xpress HD17 2011 is rated for 5 passengers, while the Xpress SV16CC 2009 caps at 3. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Xpress HD17 2011 could be the deciding factor.
Bottom line: Choose the Xpress HD17 2011 if your priority is putting more people on the water - it handles 5 passengers and at 17,0 ft it has the deck room to back that rating up comfortably. The Xpress SV16CC 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 3 that costs less to run day-to-day.