20% in New Halas feels about right, maybe not really needed tbh, I felt questing there was smooth after the xp changes. 100% in DLW is just too much, it is faster now than it was when the Beta servers were released, quests are going green and grey, just a little bit of overnight vit was enough to ding like mad. 40% might be closer to what it needs to match New Halas
Did this happen yesterday? I had created a new character and 1-4.5 or so was ridiculously slow (was doing level 7-10 quests at level 3 at the post) in the morning. When I played in the evening I was leveling so fast that mobs/quests were turned green there before I finished. Also, on my first tradeskill tutor quest I leveled twice. Morning - was too slow. Evening - way too fast.