I know Altium doesn’t work, which is very important if you need to provide someone else files in Altium format. If you just want to work on designs there’s always Kicad, which is increasingly very good! But it can’t save in Altium format, and I’m not sure I’d trust it for manufacturing.

The other thing I’m missing is my 3D Gerber viewer called ZofZPCB. I’ve not gotten either it or Altium to even start.