iTunes Sink

Having some troubles with iTunes syncing again.

• iTunes is very slow, and so is syncing. Maybe my library didn't transfer properly or isn't optimised.
• Actually, syncing is much slower. It seems to get stuck on the first file.
• Sometimes it asks you to apply changes even if you didn't do anything.
• Speaking of apply changes, what's the difference between that and sync?
• It's asking me to delete all my apps if I want to sync apps, but I thought I've synced apps before. And the "after" previews of my iPhone screen show the same apps, but randomly arranged.

It feels like each sync is a gamble - you never know what's going to be changed. iTunes is flippant about your data - keep it, lose it, who cares?