John,

Singing live is nearly all I do. That doesn't mean I'm perfect. My comps usually have only 5 or 6 parts to them; verses, chorus sections, etc.

It's not a crutch. It's a technique. Plus, if I want doubled vox down the road - I've already got the takes to work from. Much of my stuff is very light singing - breathy almost. Doubling is an easy way to give meat to the vocal without it being something other than sotto voce. I like how my voice sounds doubled when I sing quietly more than if it is not doubled.

It's as much of a crutch to do this in recording and mixdown, as amplifying an acoustic guitar for live performance.

-Scott