May sound dumb, but did you make sure it is set to 1080p? When I got mine, I thought it would auto-detect like some other HDMI devices and set itself for the proper setting, but it didn't. I forced it to 1080 and it looked much better. 4:4:4, I believe the general consensus is if you set it to that and it works, leave it that way, as that is the best
I have my Denon 2900 which also does not upscale, and I have to say that I did notice that the PQ was better but not night and day better, and nowhere near as good as Blu-ray. I have since sold my 980 in anticipation of their forthcoming BD player.