Looks like the nexus 5 has a lot of lag and can hardly keep up with the iPhone.
http://m.youtube.com/watch?v=UPk1B1bxUPg&desktop_uri=/watch?v=UPk1B1bxUPg
"Honestly doing the boot up, app speed and browser test won't really make more than a split second difference"
So if you are going to boot up your phone and then immediately open an app and close it, then repeat that 11 times then you might see some utility from that test. Although I would say the test was kind of useless as the N5 kept up with the ip5s on every app until it got to one about half way through, so of course it was behind at that point. It may have just been one app that needed optimization for Android, or it may have just been one app the N5 was slow at, whoopde doo.
The grand difference was 17 seconds difference in about 2 minutes. So if you regularly speed through opening and immediately closing 11 apps in a row then you should add up all those 17 seconds you lost on the Nexus 5 over the years and see just how much of your life you wasted on it.
In real life, for the rest of us, this isn't an issue.