The Triton Boats 177 Explorer 2010 is a deep-V design and the Triton Boats 20RX3 Pro 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.
On paper these two are close siblings in the size department - Triton Boats 177 Explorer 2010 at 17,6 ft versus Triton Boats 20RX3 Pro 2009 at 20,0 ft. At 1 950 lbs and 1 926 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 250 hp, the Triton Boats 20RX3 Pro 2009 has a 160-hp advantage over the Triton Boats 177 Explorer 2010's 90-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Triton Boats 20RX3 Pro 2009 carries 53 gallons versus 37 gallons in the Triton Boats 177 Explorer 2010. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
Both boats are rated for 650 passengers - a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.
Bottom line: The Triton Boats 20RX3 Pro 2009 at 20,0 ft is the right call if deck space, comfort, and entertaining are top of your list. The Triton Boats 177 Explorer 2010 at 17,6 ft wins on trailering ease, likely lower purchase price, and simpler docking - a solid choice for a buyer who wants more boat for less money.