Considering how hard it is to get separate CDs of all the early albums, it's great that these box sets are available. It's a shame that they've split the different albums across physical CDs but I suppose they were limited by the CD box set manufacturers.
The only specific thing I can add to what others have said is to comment on the sound quality, which is rather disappointing. I suppose in this age of digital production we've come to expect CDs to have brilliant crisp clarity, which these recordings certainly don't offer. It's probably a limitation imposed by the quality of the original masters, and perhaps they could have cleaned them up a lot given more investment, which would of course have ended up coming out of our wallets, but as it is they sound distant and a bit muddy, with even the occasional apparent very brief drop-out. Not quite bootleg-low quality but certainly not top-class either. Yer gets wot you pays fer.
So, worth having if you yearn for an inexpensive and comprehensive collection of early Span, but not something to revel in sonically.