J160 performance????
This has really got my attention too!
I feel like I really MUST comment on your oberservations of the J160.
Remember that this aircraft is really a trainer plane and should be seen as a 152 replacement.
I have loads of time in both the C152 and J160.
The J160 outclimbs a 152 (by a significant margin!), is about 5-10 knots faster and does this on 14-15 lph verses 25 lph.
Sure a 152 can land in a shorter distance and at a slower speed, but try getting it off in the same distance!
Sure some other RAA aircraft might be faster, some might have more room (but not many), some climb better, some need less runway, some carry more load, some use less fuel, some are cheaper (but not many!) - BUT name an aircraft that is a better allround package?
As for the J230 I concur with previous comments - expect near 1000fpm at 100 knots.
I dearly wish I could demo to you how a Jabiru is meant to be flown - I suspect that you have witnessed someone flying not as per the flight manual.