I installed C3D2015 and all of it's accessories without error. It recognized my 3+ year old nVidia card and set H.A. on. Other than the C3D dialogs not having the Dark theme yet (nor does Sincpac, yet, it is a LOT of work to go back and setup all of the dialogs to work with the themes), I LIKE it and am considering finally moving off of C3D2012.
On my other laptop, I installed IDSU, again without error. It is only a year old, and it's nVidia card was also recognized straight away.
I have seen another user on the Adesk forums saying they've had numerous crashes using C3D2015. I have not tested for the Figures crash he reported, but I have had ZERO crashes in the 2+ weeks I've had 2015 installed. Maybe this will change when I start to use it more, but thus far, for me, this has been the best initial release I've seen.