I'm in the middle of a huge responsive site redesign and I'll just say that responsive is a lot of extra work up front, but having your site work beautifully across platforms, devices, browsers is cool. The really painful part is when you have many different layouts and per-page layouts. It's one thing to make a blog design responsive, or twitter responsive when it's basically the same layout. It's totally different to have tens of different landing pages each with their own responsive styles. Very few if any sites are doing that yet, so there aren't a ton of great examples or established patterns.