How Are Tol Drops And Xp, Compared To Herb Cave's?

I'm a level 63 Warrior, currently grinding in Herb Cave. My loot bonus is at approximately 39% (27% Pelier and 11% Relic Spear, but I can boost it further with Jera), and my exp bonus is at approx. 55% (39% Bad Wolf and 13% Relic Spear). I'm getting 400-650 XP from the mobs, and 1.6-1.8k XP from the Professor. I also get showered with lots of emeralds every time I make a moshpit and kill it, but not many items.

It is my understanding that ToL is a level 68 quest, and as such I have three questions:
-When should I begin grinding at ToL?
-How are the drops of ToL, compared to that of Herb Cave?
-Should I use Jera while grinding in ToL?

Thanks!

 

I would start grinding asap; the mobs give more xp and all the npcs you need for grinding are in a 30 block radius. in my experience, I got more drops. If you want more loot then use Jera, if not, then don't.