This set, sadly, has pretty bad sound quality, at least to my ears.
Just to give some examples, listen to the the following Lyceum '80 tracks: Duke's Travel's/Duke's End has whistling artifacts from 4:20 onwards, and the same thing happens to I Know What I Like (5:20 onwards, it's worse towards the end) and The Knife (the whole of it).
The most evident part to detect those artifacts is on The Knife, listening to the high frequencies when Phil starts to sing, around the 0:36 sec. mark onwards.
There's something like a whistle, an annoying sibilant high frequency.
That's what spoils a great part of that show.
Once noticed it can't be avoided anymore.
It's not like that on The Source 2LP radio show or some of the other FM broadcast recordings.
The Knebworth '78 tracks are very unpleasant to my ears, due to the amateurish EQ settings applied.
While not perfect, they sound much better on the raw BBC Rock Hour reels transfers that have been around for years.
Knebworth '92 isn't better than the various circulating FM recordings.
The near-complete show also exists in pre-fm form, and it is slightly better and than the box set version.
The only upgrades to sources already out there are One For The Vine on the Lyceum '80 show - Nick Davis must have come up with a new, different source than the rest of the show - and Harold The Barrel and Harlequin from the 1972 BBC Session, which both sound less compressed than the previous BBC pre-FM source.
All the other songs included in the 5-disc set are less than or at best equal to what we already had for years.