The Xpress DVX175 2011 is a deep-V design and the Xpress HDSC Series - HD20SCA 2008 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.
On paper these two are close siblings in the size department - Xpress DVX175 2011 at 17,5 ft versus Xpress HDSC Series - HD20SCA 2008 at 20,0 ft. At 1 215 lbs and 1 190 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.
Both boats share a closely matched power ceiling - 115 hp for the Xpress DVX175 2011 and 130 hp for the Xpress HDSC Series - HD20SCA 2008. 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 Xpress HDSC Series - HD20SCA 2008 is rated for 6 passengers, while the Xpress DVX175 2011 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Xpress HDSC Series - HD20SCA 2008 could be the deciding factor.
Bottom line: Choose the Xpress HDSC Series - HD20SCA 2008 if your priority is putting more people on the water - it handles 6 passengers and at 20,0 ft it has the deck room to back that rating up comfortably. The Xpress DVX175 2011 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.