The dungeon xp buff seems very substantial. I don't know if it's consistent in all levels since I'm too lazy to scour my old logs to figure it out, but I did a 85 dungeon run right before maintenance and again after maintenance, and it's a flat 50% more xp. Got about 4m xp from one run(need 8.2m to level), although I had a little rested xp from the maint, so probably close to 3.8m or so without the rested. That's likely gonna be 5 dungeon runs for the 2 level range, versus 7 before the patch.
The daily hunt buff seems to be about 30% from what I remember, but these vary based on lvl so I might be off a bit. That's still very good, on the same 85 char, every daily hunt mark is 210k xp. That's 216k x 15= 3.24million xp for like ~5-10mins of flying around and bopping random mobs. Unbeatable amount of xp for the time required besides like the weekly WT turn in since that takes also 5-10mins but gives half a level, but the hunt marks are daillies. Definitely don't sleep on these if you have been(they were ok before, pretty sure on this char prepatch they were 160k each so 2.4m which was already pretty solid), they can be done between queues too since it's just random mob killing.