Of course Chrome for Windows is the fastest, the Windows version of Safari sucks. Like OS, like browser.
CMD-Z?
I just tried it, and it doesn't work for some reason 🙁although cmd-z does the job 😉 (honestly, I'm not sure if it's a default command or came with glims) there are plenty of missing 'peanuts' which makes you wonder if apple engineers are really focused on the customer's needs 🙄 if every amateur developer can build an addon which enables such features, why does apple refuse to do so??