-- After I've spent years carefully curating My Contacts, they've gone and dumped that. I can't tell if they actually lost all that information, or simply de-connected all of the users that I had merged by hand, but the counts are *way* wrong. They offer to automatically re-merge everything, but to say the *least* I do not trust them to get it right.
-- The UI is very pretty, yes. It is also inefficient, with gratuitous use of modal dialogs. It forces you into Google+, with all of its ticks and quirks and excessive information that I don't give a good goddamn about.
-- Because it is now all Google+, it pops up *every goddamned IM* in that window, and I can't figure out how to turn that off! I don't *want* my IMs to show up in this window -- that's what I use Pidgin for. Google+'s Hangouts are intrusive, loud, use screen real estate incredibly inefficiently, and just plain less pleasant to use. But of course it looks like Facebook's Messaging, so it *has* to work like this, and god forbid they should provide an obvious way to opt out of this UI. (This is, I should note, one of the primary reasons I do *not* leave Google+ open: those damned Hangout notifications are crazy-loud, and I don't want them.)
-- It forces open a new window, rather than being a tab inside Gmail the way it used to be. This is *way* less convenient, IMO.
-- It doesn't let me copy a freaking email address! Seriously: if I right-click on an email address, it doesn't even recognize it as a link. The only thing is lets me do is open an email in Gmail, failing to understand that the entire world does *not* revolve around Gmail. So I'm left with no choice but trying to highlight and copy the text of the email itself -- which isn't easy in this new over-splufty UI. This is a huge fail: being able to copy email addresses where I need them is the single most important feature of a contact list, IMO, and they've actually made it worse than it was.
-- And it seems to be inescapable. I clicked on "Leave the Contacts preview", which opened the old-style UI. Great -- until I went to Contacts again, and it forced me right back into the preview again.
I'm appalled. These changes appear to have been designed for looks and corporate mandates more than usability, and doesn't seem to have a functioning escape hatch. Big fail in my book...