Matching a inflatable rigid Zodiac 300 2009 against a inflatable non rigid Zodiac Zoom 350 S 2011 means you're likely deciding between two genuinely different on-water experiences. Hull type shapes everything from ride quality and fuel burn to dock handling and resale trajectory.
Both boats share a closely matched power ceiling — 10 hp for the Zodiac 300 2009 and 20 hp for the Zodiac Zoom 350 S 2011. 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 Zodiac Zoom 350 S 2011 is rated for 5 passengers, while the Zodiac 300 2009 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Zodiac Zoom 350 S 2011 could be the deciding factor.
Bottom line: Choose the Zodiac Zoom 350 S 2011 if your priority is putting more people on the water — it handles 5 passengers and at 11,5 ft it has the deck room to back that rating up comfortably. The Zodiac 300 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 4 that costs less to run day-to-day.