They're both pretty manueverable, if you know what you are doing. My inboard has opposite reverse behavior to my old outboard sled. That is, to move the bow right on the inboard when in reverse, I turn the steering wheel to the right, rather than to the left as was the case with the outboard.
My inboard (Northriver) corners much better than the outboard (old Almar) did, but I think that's mostly due the hull being better. With the inboard, I can spin the boat within it's own length. However, I could do that with the outboard boat, too.
The Sportjet inboards aren't any heavier than a comparable outboard. You do give up the space for the doghouse, but you get great power and shallow draft. And you get a spot on the back of the boat for a cooler and a place to sit while driving the kicker. I love mine, can you tell???
One big difference between the two is the steering ratio - how many turns of the steering wheel does it take to move the outboard or jet nozzle from lock to lock. Because the outboards need more leverage to move the weight of the motor, they seem to get a high ratio steering gear, so it takes more turning of the steering wheel to get the same effect. I think this makes the inboard feel more nimble.