[chrispenycate]

You can't attach the wings too high, or the body would dangle down from them; adequate for brachiating, but lousy for flying (why most griffins look wrong in flight; with a weight distribution like that, they'd dangle from their shoulders like a kitten being carried by its mother. To balance a body like that, you'd need a brain made of plutonium - and yes, I know some people who wouldn't reach critical mass even then, too)
With bat-style wings you could have an extra joint, so the "point" of the wing is well above the head in rest mode, but this is much harder to fold with feathered. Taking off from the ground would require a lot of space; it would probably be wiser to live in the upper stories, and launch off a fairly sheer drop. VTOL humans are definitely fantasy. And are you intending to sacrifice the upper limbs (as with birds and bats) to get your wings, or add them to the already existing structure (as with insects, dragons and griffins)? It makes a difference to the desigm parameters.