I have used a 300mbps wireless router for a few years. I thought the faster the better so I got the top of the line for our LAN. What I noticed with rokus (wireless) is that on gridscreens with lots of graphics it would slow down, or stop loading images, or take minutes to populate the screen even though it said the connection was 'good'. Every channel I tried said good. We would watch a video and return to the gridscreen and it would stop displaying thumbnails, or it would take minutes to buffer the video, or just plain stop responding altogether. So I changed the wireless to 54mbps and now all the problems are gone - it's streaming videos fine, they buffer fast, the thumbnails all show up quickly, etc. We've been testing in the home with roku 3's - is there some reason they react badly for this with 145mbps and 300mbps settings in the router? Maybe roku 4 will have 300mbps as 300mbps has been available to end users for over 7 years (2007?) -- how long does it take to get newer hardware to a consumer device like this? If it already has 300mbps, then I'd request an actual working implementation...instead of whatever it's using now.
Even with 54mbps that is enough bandwidth for us to stream to three devices with our 1.5mbps encodes, so we're not in a particular situation to need anything faster, just it would be nice to have some bandwidth left over for other wireless internet connected devices to continue to function. I think if you have one device at the lowest speed it slows or impedes other devices which could go faster.