From a Hackernews point of view the most relevant part of this will be their video distribution platform 'All4' (previously '4 On Demand'). All4 is one of the buggiest platforms of all of the big channels. The others may be lacking in features but even Channel 5 has a pretty smooth user experience. All4 consistently crashes, shows ads but then no programme, doesn't show programmes in its search results, doesn't keep…
Interesting viewpoint. While using the service on iOS, with an active ad-free subscription, I haven't noticed any of the issues you mention. Other than sponsorship unfortunately still being required for a small subset of programming. But other than that, the app has been a pleasure to use, far more so than the streaming app from Channel 5 which seeks my position each time I press the Pause button. I now generally rate the UX of All4 above the BBC iPlayer, which was the gold standard for a while.