I was under the impression that level syncing allowed players from all levels to team up with lower level buddies who were constantly stuck seeking a party of players their own level, and that books were to help players to earn experience point bonuses, gain buffs, and a little extra gil to allow for solo play.
For a short while it seemed to work...people teaming together in zones like Valkurm, Qufim and Yuhtunga Jungle and partying together without the fear of outlevelling each other. That was, until people discovered that by teaming together in an alliance in dungeons and doing ground valor pages over and over fighting easy prey targets gave more experience points for less effort. This coupled together with lower levels being taken to Zehrun Mines by higher levels to leech from the ground valor manuals and Abyssea alliances with lower levels taking advantage of the domninion operations manuals means that once more zones such as Valkurm Dunes, Qufim, and the two jungles have become abandoned zones with players still stuck seeking for a party if they are wanting a legit party or the book burning alliance for their level is full.
My question to SE is was this intended? To have players take part in mindless zerging or leeching without needing to upgrade their gear or spells until they hit level 90 within a couple of days with no decent skills? There's another game that does this, it's called World of Warcraft, and I came to FFXI to escape from that.