[jcommin]

I have a variation of this:

I have used half/half instead of water
I have used just the yoke instead of the whole egg. I usually mix the egg yoke with the vinegar.
I like butter better than shortening but the butter needs to be cold. When mixing, you want to see small specks of the butter. I thought the secret to a flaky crust was not to over work the dough.

I usually get the dough very cold before rolling.