Is there a particular reason that quests logs and other player data like counters aren't maintained by the server, other than to save space? For daily quests, I could see space becoming an issue, but maybe those could be kept client side only. Especially now with an Android client, I've been hesitant to start or continue quests when on my phone because I don't want my quest logs to get out of sync. I'd synchronize them myself but you need a rooted device to access them on Android. I just don't generally feel that this is an issue that players should have to be concerned with.