When should you . . .? When you don't want to or can't quilt it yourself and are willing and can afford to have someone else do it.
The thing that got me into quilting was looking at a photo of the stitching on a quilt and thinking, 'That's insane. I'm doing that.'
So the real point of pleasure for me is to do it myself. In the end, I haven't done much hand quilting because of back trouble that severely limits my ability to sit. Machine piecing, with it's short periods of sitting and standing, is what is accessible to me right now, so that's what I mostly do. Heaven to me would be sitting for as long as I wanted to, hand stitching.