But I still think it's mostly a hollow offering since they're the ones collecting and profiling us the most (or perhaps tied with Facebook).
Better yet. Use noScript, ad-blocker, flash-blocker, don't use Google services (or at least use privacy mode on search), in addition to opting-out from Advertising cookie[1].
[1] Google Advertising Cookie Opt-out: http://www.google.com/privacy_ads.html
Double-click Advertising Cookie Opt-out: http://www.doubleclick.com/privacy/dart_adserving.aspx
As for me, the least I can do is to support a company, while not with a perfect track record, has championed and fought for an open web with plethora of free and exceptional services.
I can live with that, knowing that I have the option to opt-out whenever I want to.
"And what's to stop ISPs logging the plain text https urls you access anyway?"
URLs aren't sent in plain text over HTTPS.