Yep, I started looking at the Challenger, with the single 215. The 08 at the time was a leftover. IMO it's really a 7 person jet ski with lots of storage and seating for 7. It's sooo much fun to tease those on the jet skis , most aren't aware how fast and agile these are. The look is priceless when they pulll along side and say "I can't believe that thing stuck with me"
On the bimini I usually can cruise about 25-30 if you really tighten up the straps . There is some buffeting that starts about 25. , but I've never had it parachute on me. If I want to get somewhere fast I just lower it and its go time. 45 seconds to raise it back up.
I've never had issues with low speed steering. Just have to leave the throttle(s) in either forward or reverse. If they are all they way down yes it can be a little different but with practice I got the hang of it pretty. No I get what your saying, there is no steering /dock assist on these boats. I've seen some people install Cobra Jet Steering ( I think thats what they called it ) and it helped. This was my first boat and a jet at that. I never had the experience to compare it against an outdrive. The learning curve isn't so bad. The only advice on docking is slow and come in at a 45 angle . I constantly work the levers F and R during that period up to the dock. Seems to work well for me and I've stuck to it. Sounds cliche' but that just takes practice and patience.
Hope it helped