Inspired by this thread - what do you consider a better secondary stat for PvE - crit or haste? (assuming +hit capped)

Since lava burst is guaranteed to crit, it doesn't take advantage of +crit, which also goes for FS ticks. Since burst is also on a fixed CD, it suffers from less advantage of haste as well. The question is what it more of an advantage, +haste or +crit. I'll probably need to do some number crunching, but my preliminary thoughts:

LB benefits fully from haste, FS partially (subject to GCD), CL and lava burst only marginally (cast time, but fixed CD).

LB and CL benefits fully from crit, FS partially (only initial application), and lava burst not at all.

Our primary stat is spellpower, without a question, but give the choice between an item with +spellpower +haste and one with +spellpower +crit, what do you choose?