When two boats share the same hull type — in this case both the Monterey 320SY 2009 and the Monterey M5 2010 are modified vee designs with fiberglass construction — the buying decision usually comes down to a handful of practical questions: how many people are you putting on the water, how far do you trailer, and what does your tow vehicle weigh?

The power gap is worth calling out. Rated to 425 hp, the Monterey M5 2010 has a 105-hp advantage over the Monterey 320SY 2009's 320-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Monterey 320SY 2009 carries 18 gallons versus 8 gallons in the Monterey M5 2010. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.