Mountain burned brightly in their short career, and they burned brightest on their first 2 albums. This box has 3 studio albums: 1) Climbing (1970); 2) Nantucket Sleighride (1971); and 3) Avalanche (1974). The first two are classic albums - essential for fans interested in the history of heavy metal/hard rock genre. The good news here is that they are definitely remastered (these boxed sets are hit or miss on remaster editions - if it was remastered before the set issued then it is usually included - they have not specially remastered any of these discs for this box set release). Avalanche is not remastered, but to tell you the truth, I couldn't tell the difference, and there's probably not much on it that you would care about unless you're an odd duck like me that likes one particular song off the album that nobody else likes.
The other two albums are live or half studio/half live: 1) Twin Peaks (1974 - Double Live Album); 2) Flowers of Evil (1971 - Side 1 Studio & Side 2 Live). Twin Peaks may be remastered because a remastered version was issued in 2006 and this box set was issued in 2010, it sounds good, but like I said I couldn't tell much difference. Flowers of Evil is not remastered but the sound is still good for what it is. Twin Peaks was considered by All Music Guide to be a good document of their live show, back then they used to drag songs out forever live and Nantucket Sleighride runs over 31 minutes. Most people would be happy with the Best of Mountain, which has been remastered by the way. But with this Box set you get everything that's on the Best of Mountain and a lot more for not a lot more money.