A:Answer This will be an upgrade. Both routers are wireless AC, and both are dual band. However, the Linksys has the advantage in that it has MU-MIMO (Multi user-multi in multi out). Meaning another device using your wifi won't bog down your bandwidth while you are streaming video.
Now all of this depends on your incoming bandwidth from your ISP. It cannot improve that.
There are also other factors that affect wifi signals that any router upgrade can't fix either. Such as router location, interference, radio signal blockers (concrete, metal), etc. . .