Meteor 40 would be better than Meteor 30 with 400% Explosive.
if you feel that you were doing better with the spike damage with Explosive, you can always put it back. Meteor 40 is more consistent damage over time.
Meteor 40 is only 3 Meteors dropping, but when you get Meteor Proc, 6 Meteors drop! also, Meteor Proc has same cooldown as the skill, OH!, and with Elements Set, even more Meteors! plus, I see you have Aftermath Bonus, so Meteor is doing 2550% weapon damage, half for the 2 extra meteors. if you get Elements & Meteor Proc at the same time… 9 Meteors!!!
with Shatter having a stun chance, the Taunt & Fear from Aftermath is going to be bad for monsters.