Found this thread when looking into exactly the same "soft" image quality on any BT UHD youview box compared to live aerial DTV channels direct to TV. I also have better quality images across the board, and found turning the youview upscaling off gave some improvement.
I have also had BT engineers comment that the BT youview and human source u it's are not so good at delivering the best image quality when compared to freeview by aerial or satellite receiver signals. In short, not the best boxes around, I too will not be renewing my BT TV service at the end of contract. Thanks folks
I have the UHD Youview box and it's not as good as my Sky boxes but its still a decent picture. I'm also quite fussy when it comes to PQ but am happy enough with it.
That's just my opinion though.