Each soundtrack is spread across 4 disks (so 8 for both) and comes with a 12 page booklet. The Path of Radiance soundtrack includes 64 tracks, while the Radiant Dawn soundtrack is a bit bigger at 85 tracks. Of course, these are the same number of tracks as in the games’ sound rooms.
Hopefully this is a sign of further celebrations to come, seeing as 2015 is the series’s 25th anniversary! Judging from the soundtrack descriptions, there’s a possibility more previously unreleased soundtracks might be coming too.