The spec sheets list the Beavertail 54 in. Wide Bottom 2010 as flat and the Beavertail Stealth 2000 2011 as other, so check how each hull rides in the conditions you use before you decide.
For family outings this is probably the sharpest distinction between the two. The Beavertail 54 in. Wide Bottom 2010 is rated for 4 passengers, while the Beavertail Stealth 2000 2011 caps at 3. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Beavertail 54 in. Wide Bottom 2010 could be the deciding factor.
Bottom line: Choose the Beavertail 54 in. Wide Bottom 2010 if your priority is putting more people on the water - it handles 4 passengers and at 16,0 ft it has the deck room to back that rating up comfortably. The Beavertail Stealth 2000 2011 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 3 that costs less to run day-to-day.