I haven’t done an exhaustive search, but it looks like the update has set the exp/oil ratio at about 4.85 for every battle. That’s considerably lower than it used to be, but at least we don’t have to grind SR3 until our eyes bleed. Assuming there’s no secret grinding spot, people are pretty much free to level anywhere now. Things to keep in mind would be:
1) Surviveability – If you’re grinding out your oil you want to try and avoid losing tanks.
2) Speed – It’s nice if you can beat the level quickly.
3) Rewards – Some fights give better emblems and tanks than others.
I’m liking The White North 1 right now because it’s level 32 and has no defenses at all. I haven’t repeated enough to comment on the rewards yet though. Feel free to share your favorite spots below.
It helps but in the end after some discussion we realized that there will always be a place ideal for grinding. That said we are considering special event battles for XP gain so players can vary things up when grinding. First though we need to refactor a lot of things on the backend side because its been preventing us from adding new features.