Overflow experience is a feature that I've liked from the start, however at level 70 it used to take quite long to level up. At 1,785,000 XP a pop, it took me quite a few play sessions to level up even once, and for that much effort the rewards often felt lacklustre.
Since Lost City of Omu was released, I noticed that I was suddenly levelling up much more quickly. At one point I managed to get three level-up rewards in a single play session! A quick Google search revealed that as part of this latest update, Crypic smoothed out the XP curve from 60-70, which apparently also reduced the XP requirement to level up at 70 to a measly 100,000 XP. That's less than 6% of the old requirement!
And I'm absolutely loving it. It makes playing at max level feel so much more rewarding, even more so as you have a chance of getting the 30,000 rough astral diamonds reward multiple times a day if you're lucky. For me that's a considerable cash flow addition!
Of course, knowing Cryptic's modus operandi whenever it has been too easy to earn AD in the past, I expect that this will be nerfed again soon, but I'll definitely enjoy it while it lasts.