Tested the GO yesterday. In short;
For 200-ish $/€ its amazing you can actually do vr now.
For not too complex models it works better than expected (150k poly).
Not always getting 60fps but for archviz of designs for my clients that is no problem. Again - its only €200.
I expect optimizations / changes to the model will be needed for a stable 60 fps / 72 fps.
Using free locomotion works quite ok. Haven't found templates for teleportation for the GO yet(or Gear).
Having 'just' 3 degrees of freedom (rift/vive have 6) isn't a real problem for evaluating an office or house. Sure, when you're used to 6dof you will miss it a bit.
Using Unreal Engine, you do need to make a separate project for the GO because several settings must be changed and UE will re-calculate all shaders for the GO (optimizations, loosing some fancy effects in the process).
This way, you can't have just 1 project that runs fine on desktop, fine in the Rift and fine in the GO as well (until now I did have just one project for desktop & Rift).
You probably also have to do optimizations to your 3d model / project for it to run nicely on the GO. That can turn into a time sink.
Using an Oculus Rift for the last year, quite early I upgraded my gtx1060 (that runs fine with most of the AAA-games) to a gtx1080 just to get more gfx power so I could import any 3d design without having to do optimizations to the model for it to run nicely.
With the GO that will be different I expect.
Still have to do more testing...