I originally looked at the Jet Boats because of their low draft, high freeboard, big V, twin engines and large swim platform.
Cons: They don't displace water to make big wakes, reverse just as useless as an inboard, fit & finish (gaps, quality of vinyl, cheapy trailer).
I would disagree about the fuel consumption, they should be fairly close. I think bocheus was thinking about the Big Block flat bottom jet boats, not the recreational jet ski motor driven boats from Yamaha and Sea Doo I think you were referring to. I grabbed these from boattest.com. I don't pay to get the archives so the best I could come up with for the Inboard was an RZ2 with the 5.7L 360HP Marine Power vs. the dual 160HP Yamaha.
RZ2 SX230 HO If you look at the 0-30 and time to plane they are pretty competitive.