The new bike certainly is different than the old, but I completely disagree with some of your thoughts.
I agree the motor is fun. However, it's quite different than previous boxers so I suppose it's what you're used to.
Handling is much quicker with the COG lower. I like it, but I'm sure some may not. To me, even though it's dimensionally very similar in size and weight to the outgoing model, if feels much smaller. Combine with the motor, it feels almost as if I'm on a sport bike without the cramped riding position.
I disagree with the windscreen though. I'm curious as to your size. My '07 GS with the stock screen sucked. Very loud and turbulant. I also had a '13GSA on loan while I had some warranty work done to my new bike, and even with the winglets and larger screen, the air was loud with lots of buffeting to my helmet. The GSA does win in blocking air to the lower body with the big gas tank but that's obvious. I did order a new CalSci windscreen for my GS which I'm still waiting for, but even the stock screen offers much better wind management than the previous models.
I also disagree with the "sliding around the bike." Huh? Do you not grip the bike with your legs?
Lastly, how is the front end scary? I don't get that at all either.
Personally, I like the freer revving much sportier feel of the bike while still offering everything I liked about my previous gen GS. Also, while I loved my old GS, it did feel big and and semi lethargic in comparison. It's all personal taste obviously and I'm sure many may not like it. I can respect that, but there are a few issues you mentioned about I'm quite confused about.
'15 KTM 500 EXC / '13 BMW 1200 GSW / '05 Honda ST1300 / '04 Husqvarna TE510