I cannot grind exp if the progress is too slow, it drives me crazy. Collection quests made this a bit more tolerable because it gives me something else to focus on, that can be completed more quickly than the exp grind (even the worst collection quest requires fewer kills than grinding out a level, after all). Some collection quests are bad in that the mobs you need are scattered all over. The wolf pelt quest would have been torture except for the fact that I knew I could grind on the spiders at the same time and gather silk for the 18 slot bags. I think that over the relatively short time I spent in Outland, I made three 18-slot bags per character. If I had to grind those out just for the silk, I'd have given up after about one bag.