The Xpress Recreational - 1650LO 2008 is a flat-bottom design and the Xpress X21 2011 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.
Size is the most obvious dividing line here. The Xpress X21 2011 measures 21,3 feet overall (2011), giving it roughly 5,3 additional feet of deck space compared to the Xpress Recreational - 1650LO 2008 at 16,0 feet (2008). Weight tells a clearer story for trailering families: the Xpress X21 2011 tips the scales at 1 580 lbs - 1 196 lbs less than the Xpress Recreational - 1650LO 2008 at 384 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.
The power gap is worth calling out. Rated to 250 hp, the Xpress X21 2011 has a 220-hp advantage over the Xpress Recreational - 1650LO 2008's 30-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load.
For family outings this is probably the sharpest distinction between the two. The Xpress Recreational - 1650LO 2008 is rated for 5 passengers, while the Xpress X21 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 Recreational - 1650LO 2008 could be the deciding factor.
Bottom line: Choose the Xpress Recreational - 1650LO 2008 if your priority is putting more people on the water - it handles 5 passengers and at 16,0 ft it has the deck room to back that rating up comfortably. The Xpress X21 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.