Obligatory plug for my AP thread, it's got a table of how long it will take you to reach each level based on getting 2600 AP a day essentially. Your mileage my vary.
As far as NL is concerned, it's much faster then TW, especially as you get more gear. I've manage to hit the lockout period now, and am still averaging a 57% chance for AP over 190 chests. That being said, Timewalking is great for ones sanity, and if you had a crew of 5 with proper gems and coordination you could probably have a comparable rate while making a decent amount of gold off DE'ing all the blues into leylight shards.