Desert Storm (3.5, Feat, ToB, PEACH)

[Zaydos]

Desert Storm:
The desert wind is scorches those within it, but occasionally even in the desert a powerful storm brews sending freezing rain and terribly lightning down on those within.
Prerequisites: Any 2 Desert Wind maneuvers.
Benefits: When initiating a Desert Wind maneuver that would normally deal fire damage (or grant you bonus fire damage) you may reduce that damage by 5 to deal Cold or Electricity damage instead of Fire, or by 10 to deal Sonic damage.

Is this a worthwhile feat? Would you take it?

[~Corvus~]

Desert Storm:
The desert wind is scorches those within it, but occasionally even in the desert a powerful storm brews sending freezing rain and terribly lightning down on those within.
Prerequisites: Any 2 Desert Wind maneuvers.
Benefits: When initiating a Desert Wind maneuver that would normally deal fire damage (or grant you bonus fire damage) you may reduce that damage by 5 to deal Cold or Electricity damage instead of Fire, or by 10 to deal Sonic damage.

Is this a worthwhile feat? Would you take it?

Look at Energy Substitution (Complete Arcane pg 79): perhaps require 5 ranks of Martial Lore instead of damage sacrifice. Sonic is rare for monsters to resist, so it would totally be worth it with those changes.

The best DW maneuvers are ones with utility:

Wind Stride grants +10 move speed (tends to be amazing even at high levels)
Burning Brand grants +5-foot reach (and negligible extra damage)
Flashing sun does an extra attack at low levels
Searing Charge allows you to negate death from a fall of any height with fly (perfect)--all you have is to attack the darkness (http://youtu.be/O_aJgcVv62Y?t=44s)
Salamander Charge creates a shapeable wall of fire

With the "feat" as it is, the 6th level Fiery Assault stance is practically worthless, only adding 1 bonus damage ~17% of the time. Although the higher-damage abilities like Ring of Fire, Fan the Flames, and especially the 9th-level capstone wouldn't suffer much from a -5 or -10 damage, the rest look even more unappealing.

[Just to Browse]

Desert Storm deals piddly damage as it is, so people only pick up the non-damage stuff it provides. I wouldn't take this feat and just deal untyped bonus damage with Diamond Mind or something.

[Xefas]

Is this a worthwhile feat? Would you take it?

Maybe. With a little tweaking.

Desert Storm:
The desert wind scorches those within it, but occasionally even in the desert a powerful storm brews, sending freezing rain and terrible lightning down on those within.
Prerequisites: Any 2 Desert Wind maneuvers.
Benefits: When initiating a Desert Wind maneuver that would normally deal Fire damage, you may instead deal Cold, Electricity, or Sonic damage. If you choose to deal Fire, Cold, or Electricity damage with this feat, increase the amount of damage dealt by your initiator level.

[Zaydos]

Does it matter if I clarify it to work with the boosts (as it was intended to) which add Initiator+Xd6 level damage to all attacks for a round?

[~Corvus~]

Does it matter if I clarify it to work with the boosts (as it was intended to) which add Initiator+Xd6 level damage to all attacks for a round?

The boosts add 1d6/2d6/3d6 +1/ilvl fire damage. The errata did not address it to make them xd6 damage. Simply put, detracting damage to change energy types does NOT make it attractive. Making the boosts more powerful isn't really attractive enough, either, because that's a feat to make 3 maneuvers better (burning/searing/inferno blade)

[Just to Browse]

I think Energy Substitution is a fine place to start from when looking at a feat like this. E-Sub requires 1 metamagic feat, 5 ranks K(arcana), and lets you change all damaging spells into the chosen type, at your discretion.

I feel like limiting that to only 1 discipline would be worth the tradeoff of gaining 2 separate damage types, no need for a drop in the damage provided.

[Temotei]

I feel like limiting that to only 1 discipline would be worth the tradeoff of gaining 2 separate damage types, no need for a drop in the damage provided.

Agreed. Even without a damage penalty, it's not top priority, though it works.