I've had formatting issues with the responsive site, when posting from a phone.
This is what it looks like on the old website:
EWR:
I’m often posting from my phone.
This is what it looks like on the new website:
EWR:
I’m often posting from my phone.
I guess once the old website goes offline, this won't be a problem anymore. Still I thought I'd mention it.
Aside from that, while I'm generally in team "If it ain't broke, don't go fixing it", I already see some positive in the new responsive site. It will take some getting used to, but I'm sure I'll love it soon enough.