When To Do Tower Of Ascension?

I'm confused about the tower of ascension. When should I be able to complete it? The reward is a level 75 set, is that the appropriate level? Level ranges are confusing.

 

ToA is supposed to be done at 75

 

Its something you're intended to do as you level. Every 10 levels or so you can check back and go through another set of floors. Most people just wait until 75 and do it all in one go however.

 

75, since that's when you get the most xp. you can go back to do it as you level up, though it's easier to just do it all at level 75

 

This is not official, but I see it as a challenge to try every 10-15 levels or so, up until level 75. So at level 40 I see how far I can come, then at level 50, 60 and eventually I try to finish it at lvl 75.

Way back before Gavel, the level cap was 75 and ToA was the "ultimate challenge" to be done after you've defeated CoW and Bob. Hence, it is very hard to complete under level 75. Moreover, you get max xp when you finish it at lvl 75 or higher.