I use LL/Meteor/DS/FN/EB , and honestly I dropped cold blooded for prodigy because it makes windup insane, and I was out of ranging my frost nova for more than half my targets anyway. 18 apoc, 52% crit with pinpoint.
The thing that makes CM work is CRITS OVER TIME. With WW you have 6 seconds per cast for crits to return resources and cooldowns, with LL you have more like 2 seconds per cast. With meteor you have 1.5 delay, then 3 or 8 seconds.
Regardless of clean-room Math the real physics differences of meteors really matter - maybe even more than the proc rates or return potentials.
With WW you should be locking down most things so Liquefy is an attractive option, and of course DOT is the way to go for bosses, but if you are running for xp, nothing you run in to should be surviving long enough in one place for an 8 second DOT to matter, even elites.
Molten impact is awesome single target, but again unless they are locked down anyway, you get misses and misses pretty painful when they cost half your AP and don't return anything. Still, if you are running with EB as your main damage dealer, Meteor is just extra dps when you need it anyway, so if you don't need it to pay for anything, might as well use the biggest hitter.
So missing or not locking down in the DOT is meteor's greatest weakness, and not locking down is LL/CM build's greatest weakness. Liquefy and LL don't synergize well because of this, the 8 second DOT isn't going to help enough for total lockdown, especially if you are trying to throw out more Meteors+123 instead of constant LL+123
Shower doesn't miss as much because it covers more area. And that is almost all you need to know... So to get less misses, more average crits over time, and more versatility for XP gain LL/CM/Shower is just better.
Also with decent packs shower is self-sustaining for me once I reach windup, none of the others are.
Also try hitting the A3 keywarden or a fast leaper with anything but shower.