Stylo a bit slow?

When I first got the G Stylo it was by far the fastest phone I've ever had and it still is, but I had to get a replacement phone a couple times because the GPS on the previous phones were straight up trash. Finally I get my hands on one with a perfect GPS... and now I notice that it slows down a tinyyyy bit during the day. The phone still works great but I did notice that in a couple RAM booster apps that I downloaded (I've been trying out different RAM boosters, not all at once) and they all say that there is a total of 1.86 GB of RAM, not the full 2 GB of RAM that Metro said there was. Could this be an issue?

Also my phone is not Rooted. It's stock with Android 5.1.1. with Software Version MS63110J

Also do you think the Stylo will get the Android M update?