I own all of the Archive Series releases so far. Haven't listened to all yet but so far they are excellent. The box mentioned by the OP just arrived yesterday.
Joni Mitchell remasters on the way
FYI, some remastered Joni albums from an amazing period are on the way. I’m especially excited about how "Miles of Aisles" turns out, because that album really needs a remaster.
"Rhino explores the beginning of the prolific Asylum era with THE ASYLUM ALBUMS (1972-1975), the next installment in the Joni Mitchell Archives series. The collection features newly remastered versions of For The Roses (1972), Court And Spark (1974), the double live album Miles Of Aisles (1974), and The Hissing Of Summer Lawns (1975). All four were recently remastered by Bernie Grundman."