Yup depends on your needs. We're going from a 20.5 ft cuddy I/O to a 19.5 ft bowrider with a jet engine - usable space is almost double. We originally thought we'd have to go with a 21 ft, but once we saw how much room a 19 has, we stopped looking at larger boats.
As for fuel consumption, a single supercharged 1.8l uses about the same as twin N/A 1.8l engines so it would have been a wash either way for us. The twins do have more "torque" to get you moving (good for tubing/waking), and more top end speed (48 vs 51). And the extra 1000 lbs helps in heavy chop. Maintenance is light on jets, so it's basically oil and spark plugs x 2...not a huge increase in operating costs overall.
Besides, boats are luxury items intended to be fun, not daily drivers to go to work. Get out and have fun!