I'm not sure I was clear before. As far as I know, it is not "farming processing out to the cloud". The processing happens on the phone you're carrying.
In other words, if you already carry a smartphone, you are presumably not giving Google substantially more data than they would already have from your use of the smartphone. And, as I said, it seems like it's easier to control Google's access to data on your smartphone than on Glass (custom ROMs, etc.).
I haven't tried flashing my Glass yet with anything other than the stock ROM, but I know people have done this with success. So that route is open if you want to really lock it down.
In other words, if you already carry a smartphone, you are presumably not giving Google substantially more data than they would already have from your use of the smartphone. And, as I said, it seems like it's easier to control Google's access to data on your smartphone than on Glass (custom ROMs, etc.).
I haven't tried flashing my Glass yet with anything other than the stock ROM, but I know people have done this with success. So that route is open if you want to really lock it down.