When I designed the new file formats I had no idea that a lot of applications (though primarily email and browsers) tend to rename files that are pure XML. If you want a safer way to share Grasshopper data online, use the *.gh flavour instead of the *.ghx flavour. GH is a binary format so it's way smaller than the textual GHX and it also doesn't get re-interpreted by any other applications.
Assuming that I save one same GH defination as both binary and xml format, are there any differfence between the binary format and XML format files while I am trying to open them again?? I mean efficiency mainly .I am thinking if the binary format file is "better" or at least not worse than xml format while they are thinner at the same time,why don't you set binary format as the default format when save gh defination ?just curiousness.