If you haven't already, take the time to read Les Orchard's writeup on the sad state of the mobile web. A 1,500-word article that's 9.2KB of text balloons to 9.5MB distributed over 263 HTTP requests that take 30 seconds to load. That's a 1,000-fold increase.
It should be no surprise that this is one reason people are switching to mobile apps: they have less bloat.
In our case we spent significant engineering effort to bring Recent's cold boot time down to about 1 second. This meant fine-tuning our backend Python code to take advantage of the speed of Google App Engine, and performing some black magic in our iOS and Android apps to save extra milliseconds by initiating the network request very, very early in the boot process.
As you can see in the above screenshots, Recent's home tab, which provides you with a summary of your news, rendered in 0.65 seconds on my Nexus 5 and 1.14 seconds on my iPhone 6 Plus. These are cold boot times using my home WiFi connection this morning, not a special gigabit testing lab. (If you're an early user of Recent, you can see your boot times though an Easter egg on the search screen: type ///time to enable.)
News organizations could optimize for speed. John Gruber says Daring Fireball pages weigh in at a flyweight 125KB to 175KB. But while the benefits of adding more analytics code to a web site are immediately visible, the costs of additional latency are less visible and distributed over millions of readers.