SC2 will no doubt provide more reliable and bullet proof HW solution, even with these engineering shortcuts it already looks like higher end piece, just look at the Fanatec rubber grommet QR.
But there is more to the story than that, Fanatec has upper hand with sim market share and therefore support from game devs if you need Forza and such, mind you many here don't. So it's not all white and black, knowing Granite Devices experience with motors control, I bet when it comes to pure FFB feeling and tunning, SC2 will have an edge, so you would need to decide what is more important to you.
DIY SC1 is already at level or better than D2.