How to get from level 50-60 in 4-6 hours (Warning: 160% XP Vials Required)

My baby mage is going to be 50 soon so this seems like a very good leveling strategy. I do have one question: Some people recommend hitting the initial Storm legion zones at 48 instead of 50 to get a boosted rate of XP.

What are you thoughts on that?

My concern is that it'll end up costing me more time having to kill the level 50 SL mobs while I'm 2 levels below them. But with the 160% (or 200%) Xp boost, that could end up being quite effective.

 

Suggested specs, unfortunately I don't have any guides up for these leveling specs but if I get 3+ requests for a certain guide, I'll probably make it:

Warrior:
51 Tempest/ 4 Warlord/11 Riftblade
51 Riftblade/4 Warlord/11 Tempest (If no Storm Legion souls, replace Tempest with paragon)
51 Champion/11 Warlord/4 Paragon

Mage
51 Harbinger/11 Chloromancer/4 Elementalist
51 Elementalist/11 Chloromancer/4 Necromancer
51 Pyromancer/11 Chloromancer/4 Harbinger (4 Archon if no SL souls)

Cleric:
51 Shaman/15 Defiler/0 Justicar (51 Shaman/9 Druid/6 Justicar if no SL souls)
51 Druid/9 Shaman/6 Justicar
51 Inquisitor/15 Defiler/0 Justicar (51 Inquis/6 Purifier/9 Justicar if no SL souls)

Rogue:
41 Nightblade/21 Riftstalker/ 4 Tacticianhttp://forums.riftgame.com/game-discu...
51 Marksman/11 Riftstalker/4 Tactician (4 Saboteur if no SL souls)
51 Ranger/11 Riftstalker/4 Tactician (4 Saboteur if no SL souls)