Thanks for taking the time to reply Vincent, I know the Mint developers must be pretty busy right now.
For me this feels like the removal of the minimise and maximise buttons all over again. Some people will like it, some won't. In that case gnome-tweak-tool came to the rescue, allowing users to restore the old behaviour.
I'm sure some people will prefer the new behaviour (perhaps those running Gnome-Shell on a tablet?!). To be fair, the Maximus extension http://cinnamon-spices.linuxmint.com/extensions/view/19
appears to have been well received, but these changes to Gnome applications go further and there doesn't appear to be an option to revert to the old behaviour. That's what irks me - not having the option.
I've started asking questions on Gnome Bugzilla https://bugzilla.gnome.org/show_bug.cgi?id=687887
. The option to restore the old behaviour can't be incorporated into gnome-tweak-tool. My concern is that these applications might have to be forked or downgraded in order to give users the option of the old behaviour, and that would be no small undertaking. I'm really glad that the Mint developers have forked Nautilus, but it's a real shame that upstream changes meant that the Mint developers felt they had no other option, as it must involve a lot of effort.