It's certainly not a hassle having a pc under the tv. I have mine there which outputs 1080p via Windows Media Centre and have it connected to my server pc which stores films, music videos and mp3's. It's also got a Blu Ray drive. It's not masive or bulky (Scaleo E barebones, which I upgraded).
So for me, I tried the Tesco service only and plays fine via my media pc even with my dire internet connection. Content is limited, but it's early days yet.