Is this as slow as the PlusOne widget? I pulled all the PlusOne buttons from my site because, even with asynchronous loading, they were taking ages to load and seriously affecting performance of my site.

Totally unacceptable considering that Twitter and Facebook both loaded in under a second.

Agreed, same here, Twitter seems to be the most well behaved followed by Facebook but +1 is atrocious.

Also, will this now support IE7? The earlier one did not.