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.
Well said, good post, plus the Tesco service is a freebie so no harm done. If and when Tesco say you need to spend/visit/use your clubcard then its absolutely no loss at all.