Mhhh Furious Baco, anyone?
I have not had the "pleasure" to ride it, but from what I hear, it rides absolutely terrible and makes you wish you never stepped into any rollercoaster.
The idea though sounds quite great - sitting next to the track, chasing with insane speed through a low to the ground layout... I really like the idea.
Another thing would be the trains of Hyperion. A 4 across train from Intamin to allow long layouts without the need to have extreme long trains to get a decent capacity sounds great. But in my opinion, the poor execution starts with the outer seats - why are they lower than the inner ones? Maybe it is just me, but that was a disappointment for me. And then, the ride.... The inner seats are fine, the outer seats of the front row are as well... but once you step into a outer seat at row 2 or further, you will experience what rattle is. It still amazes me how not even 1 metre of distance to the side can ruin a rides experience that much.