I reckon most people have cross referenced the experience they're receiving from quests to YouTube videos, and most people probably know grey coloured quests are ones you have out-leveled. But I suppose it wouldn't hurt to clarify this.I've been reading a lot of posts, and there seem to still be a lot of confusion about how the xp works, people still complaining about getting 5 xp, yet they fail to notice, the quest is out of range (aka you are too high level for it). One of the problems seem to be that because this thread is "HUGE", people dont bother reading through it and miss some important information. So I'm going to repost what Mighty91's said which clarifies most of the stuff, hopefully CDPR will make something a small sticky thread, maybe "XP game mechanics - READ FIRST BEFORE POSTING" (just a suggestion), for people to understand how things work before complaining about a bug:
4) You get less xp for higher difficulties, so if you notice you are getting like 80% only, it's normal, it's not a bug.