This was an issue with my 64 GB SanDisk version and those on certain Lumia’s know what I’m referring to.

Navigon GPS though did throw an error at me, which was unfortunate (luckily I can just move it back). Music files and images are great, with no noticeable decline in performance. That’s not to say you may not experience such hiccups, but for the most part, it works and works well. Once the game is loaded though, I have not noticed any stuttering issues or oddities. It’s one of those things you won’t notice until you directly compare, so it’s not a big deal.

Games, like Jetpack Joyride take about an extra 1-2 seconds to load, when compared to a game stored in main memory ( Lumia Icon versus Lumia 1520, for reference). That’s not to say there aren’t differences though. Yes! It’s kind of weird, but at least on the Lumia 1520, I cannot tell the difference between the two.