Warmage vs Battle Sorcerer

[Sith_Happens]

Anyhow can someone tell me why the Spellswords Channel Spell ability is considered so good?

Because it lets you channel any spell at all, including area spells and personal spells. One the entries for the Spellsword round of Iron Chef, for example, was a Wu Jen that smacks Transcend Mortality onto things and then dismisses it to kill them.