Grasshopper on Apple MBP retina, bootcamp, windows 7 or 8, with external screen: is it working for anyone?

Hi, I'm planning to upgrade my older (non-retina) MBP to a new retina MBP, running the configuration in the subject title. However, I was reading about some people who had trouble with the icons in Grasshopper being to small on the retina screen (which is likely where my grasshopper window would end up, even if I use an external screen).

Has anyone solved it? Is anyone running grasshopper on a retina MBP to satisfaction? I'm a bit of a mac addict, but I can't afford to not have this working well...