When BarackObama.com launched, it was described at work as the best looking large responsive site. Someone suggested it was adaptive; however, I would say it’s more responsive than adaptive. The smaller sizes are responsive while the larger sizes are more adaptive. Folks bristled at all the different classifications, which makes sense. It exposes the tension people have with understanding responsive design. If you’re just starting out, it can help to get your head around fluid web design since it underpins responsive design.
Regarding Obama’s site, I can see making strategic decisions to keep the larger sizes pretty consistent and only moderately fluid in a certain range. It’s all about strategy, who your audience is (includes tons of people who’ve never seen a responsive site in action and could be surprised if the desktop and their iPad/Kindle looked quite different). They also make extensive use of video on the site and responsive video is one of the trickier parts to get right cross-device right now.
The most variety occurs at the lowest end of devices, and it’s the most unknown. At this end of the browser spectrum, there are thousands of devices and browsers. By making that part responsive, they enable device-appropriate displays of the content for the largest audience. It’s also the device set where you can’t resize your browser, so you’re stuck with what you get. With lots, if not all, tablets and laptops coming in at 1024+ pixels, the larger end of the device set is more stable and flexible to work inside for the user.
Any team that is doing responsive work should be fully up to speed on the literature out there because the landscape has changed significantly since Ethan’s book came out. His book should serve as a primer only. For instance, recent browser image fetching techniques broke the responsive image technique that was lauded by many. People are still figuring out how to do different things * video, images, feature content, rich applications. New techniques will emerge, old ones will vanish. We must avoid complacency or inability to adjust as these changes happen, altering a project or process because of new information. It requires people be aware of the advances in this area.