Best use of Exp Tonic

AS title suggest, I would like to know from veterans out there what they think the best use of these +100% Exp tonics is.

Since they are only valid for 1 hour, if quest exp is affected by it, it may be worthwhile to do 1 Crucible 1st wave.
Then go directly Act2 within that first hour where i assume exp per quest is higher ?

What do you guys think ?

Regards
Gogga

Act 3/4/5 quest xp. Late game Chtonian area farming. BoC in particular

I think it affects devotions also so u might even use a couple after lvl 100 to max out your char

The tonic works only on the current game session. Using on crucible, then exiting, your tonic effect will go away. Best to use when doing quest and get those juicy xp rewards.

Stack up completed quests and bounties before using it, use it, claim the quest and bounty rewards, then do a Steps of Torment and a Bastion of Chaos full clear run. I cannot imagine any more effecive use of it.