No, I disagree.
I'm saying there are three classifications:
Giger's Biomechanics.
AVP/A:R- Oil slick Aliens.
Prometheus- Fleshy, bony Aliens.
And in Prometheus we have tons of Biomechanics, strange thing is certain elements are, others aren't.
The Derelict is one great example, especially from outside.
And the Engineer jumpsuit, where people still question if it is a suit or has his flesh been augmented.
But the actual "monsters" in that film where never trying to be Giger, with the exception of some early Fifield monster concepts.
That's why they get a pass from me.
As for the Deacon, it isn't goopy or stringy at all.
Maybe the inside of the mouth, but that's just gums.
It happens to be covered in Engineer blood and guts but the design is exactly what it needed to be- the most basic resemblance of an Alien. Plus if you look at it not covered in Engineer blood (I believe there is photos on Strange Shapes) I think the design, even lacking in Biomechanics is pretty spectacular.
It's the fact AVP says these are the Xenomorphs you know and love- and gets the design all f**ked up that really pisses me off.