[thejeff]

It's also such a situation dependent question, it's almost unanswerable.

Immortality is great for key units, like a pretender, but unless you're dominion pushing it's really only useful on defense. And only then if you can get the troops back to the front quickly. Does anyone really build strategies around Vanheim's Fay Boars?

Some Sacreds are great, others aren't worth bothering with.
Regeneration is great on high hp units, almost useless on normal humans.

Etc, etc.