Accessing content over slower connection speeds isn’t the only issue to consider when building mobile first RWD. You also need to consider the latency and drop outs in connectivity.
I included several sites that have specific mobile web presences as well as sites which take a responsive approach. I also extended my connectivity modeling to cover various everyday connectivity conditions I encounter. Namely; at home, on public transport, at the office, out and about. Finally, I measured payloads for a series of 4 devices ranging from desktop to smartphone to feature phone. In summary, I’m looking at a mix of sites (3 responsive and 3 mobile specific), 4 devices, and 4 different connectivity models.An excerpt from Responsible Web Design and how websites cope with compromised connectivity | mobiForge