A lot of the confusion and upset over what Sky Glass is, has unfortunately come from a lack of clear information from Sky.
Coming from the postion as a Sky Q user; when using catch-up services - including for terrestrial channels - the download quality is in full HD, and in many cases there are no ads, or the ads have been dramatically reduced.
The impression I got from the launch videos and from reading the website was that Sky Glass would be similar, in that we could 'playlist' a show and (instead of downloading like Sky Q) stream it in HD when we wanted to watch it. With no contradictory information, my assumption was that Sky would serve up full HD shows on demand, as they do with Sky Q.
Once people started receiving their TV's, it became clear that many channels only serve up SD quality and stereo audio catch-up with ads, from the bog-standard third-party apps available everywhere. And even then we would have to wait for the TV show to appear in catch-up on the app.
So many of the complaints would have been prevented by being much clearer at launch about what the TV could do.
All the stuff about '1,000 hours of cloud recording' was superfluous marketing speak, and gave the impression it applied to all channels.
In reality the most convenient features mostly only apply to Sky channels, everything else (including channels showing some of the most popular TV shows) is farmed out to apps with much poorer picture and sound quality.
Of course this is absolutely fine for many users, but it should have been clearer from the start.
The main Sky Glass website is still woefully poor on detail, with links saying 'Take a closer look' linking back to the page you're already on. And I still can't find a confirmed channel list.