A big heads up for anyone thinking of switching. Bootstrap 3 "Drops IE7/FF3x support entirely."
ref: http://blog.getbootstrap.com/2012/12/10/bootstrap-3-plans/
ref: http://blog.getbootstrap.com/2012/12/10/bootstrap-3-plans/
http://clicky.com/marketshare/global/web-browsers/versions/
http://gs.statcounter.com/#browser_version_partially_combine...
If your audience is public businesses ie7 shares whill not be just 1% of your target.
If you care only about people using browsers at home,then you are not doing your job.
Can you elaborate on usage stats of "public businesses" and where you got those from?
If you have usage stats on your audience, then use them. Otherwise, go with the global usage, or at least your country/continent.