General

Post Reboot
140-250 Dimension Invasion
EXP: Crap
Spawn: 5/10
Survivability: 9/10 Watch out for green orbs fam
140-165 Temple of Time
EXP: Mediocre
Spawn: 6/10
Survivability: 9.5/10
165-250 Drill Hall
EXP: Okay/Decent
Spawn: 6/10
Survivability: 9/10
170-250 Hall of Honor
EXP: Okay/Decent
Spawn: 7.5/10
Survivability: 8/10
190-250 Warrior Grounds
EXP: Better
Spawn: 11/10
Survivability: 7/10
210-250 Black Heaven Scrapyard Maze 5 (Best EXP)
EXP: Best
Spawn: 8.5/10
Survivability: 3/10

@helpingly: Thanks

Well you can go train at warrior grounds until 210. After that you want to head to scrapyard (if you can kill them, if not stay at WG).