Tested Rebel 2017 9m back-to-back Rebel 2018 7m (on 4 lines). My impressions on 2018 are: more forgiving and better turning, less tendency to backstall, not as excellent depower. I felt less hunting of the window edge compared to 2017, so easier/more comfortable to use.
It was very gusty and I chickened out of kitelooping the 9m, but the 7m was very easy to loop. Not much of a pull, as expected of a Rebel. Very very slight lag on turns due to pulleys is nearly the same as the usual lag of earlier Rebels - I got used to it in 3 minutes and had no problem adjusting my timing for jumps etc.
The 2018 looks very Rebel-like in the air but flies more like a fac-simile of earlier Rebels. It provides similar performance but in slightly different way / different feeling. It fills the same marketing nice as earlier Rebels. It's another great 4-line Kite. Is it a good or bad thing? Dunno. Cheers and good winds to everyone!