I've followed Kopp's guide for my priest/warlock group and it's pretty much been smooth. I've levelled before with his guide so I know which quests to skip. A lot has changed in the last 6 months and the've changed the drop rate on a lot of quests. I remember tearing my hair out on the Zangermarsh area because of the low drop rates on the collection quests but it was actually much better this time around.

What I found myelf doing was skipping the short chain quests with large (>10 items with lower drop rates) and replacing them with the elite quests (Nagrand mastery quests for example) which Brian Kopp seems to skip over because they can't be done easily without a group. This way, I'm within 10% of the level that a single player would be at if soloing the quests and blowing through them quickly.

I did the instance grinds early, and like most people say, you're pretty much bored to death doing them. So getting out and doing quests is quite refreshing compared to repeat runs in instances.