Who are you asking Guaranalol? If you're referring to a collective
you, as in, "Why would I," then my answer is that Scorch is preferrable in situations in which:
- There is no Affliction warlock (see
Affliction - Spells and Rotations
- There are adds that have very short lifespans, or very short windows of DPS time, but otherwise, require relatively high amounts of burst DPS (adds on Emalon, Heart on Deconstructor, Dark Runer Watcher's on Razorscale; more examples would be here but my 10-man raid has not gone to Ulduar yet)
- You have an affinity with Scorch and just cannot give it up
- It appears you didn't read the tooltip on Improved Scorch or the patch notes, so all of these possible answers mean nothing.
Leggings of the Enslaved Idol definitely look nice. I will certainly add them in when I get home from work. Unfortunately, they may end up being another
[Leggings of the Wanton Spellcaster] -- an item that is really good, but is overshadow by set bonuses. Naturally, there is (usually) going to be 1 piece in the set bonus that you want to leave out. Right now, that is
[Handwraps of the Vigilant].
Hopefully wowhead starts being populated with more items from user-submitted data (and from wowarmory), and set bonuses can start being implemented into Rawr (someone out there already has 4-piece set).