BB-8 said:
Thanks for your response. Yes, AVCHD. I would say that it looks worst when there are letters on the screen...the opening crawl for instance. I have a 4K TV and a Sony Blu-Ray. If you're standing at the TV you can see it's not as sharp, but even just sitting on the couch it's pretty stunning. So maybe not worth getting a blu-ray burner?
That could also be that you're watching a 720p video on a 4k TV. You may not even notice a difference with the MKV.