I got my box for £17 through an Amazon pre-order sale so I'm happy! But if you are thinking of paying the full £30 asking price you might want to approach with caution. The box is stylish but mine fell apart after a couple of days. In fact the box (or is it a wallet?) doesn't close so book & discs come tumbling out. The book itself is good & Colin Harper gives a definitive telling of the Pentangle story (based on new interviews), though I would have liked more info about the actual tracks on the discs (especially as the track listing annotations are in microscopic print). As for the music, well, you get a fairly standard greatest hits selection on the first 2 discs, interspersed with rarities, b-sides, alternate takes etc. Disc 3 is the Festival Hall 68 concert, which might annoy those who got the recent Sweet Child upgrade containing the same show (albeit in different edit). Disc 4 is completely unreleased stuff (some interestingly left-field), mostly TV sessions, some with less than perfect sound quality.
I have to say that each disc is very well programmed & enjoyable. And given that Pentangle are back in vogue at the moment, it's probably timely to have a comprehensive overview rather than just a box of rare stuff for fanatics.
Initial "previously unreleased" highlights, for me, include an alternate 13 minute studio take of Reflection & a 20 minute live Pentangling from 1970 - the latter confirming how improvisational they were from night to night. Perhaps the real disappointment is that so few live concerts have surfaced. The book mentions that they used to tour regularly with the Grateful Dead & play the Fillmore, such shows were routinely taped, so is there a stash of Pentangle concerts gathering dust on a shelf somewhere in the US?
Anyway, the music on this box has never sounded so good & should keep Pentanglers old & new occupied for a long time to come - but my advice would be to shop around.