So here's a couple of screens.
http://imgur.com/a/FQDmq#0
First one is a slow build - notice textures look okay.
Second one is Full Build
Cvars haven't been touched - Miplevel is 0.
This has really stopped me in my tracks - I've posted this in another thread but I'm hoping a new topic will get more views in the hope that somebody knows something.
Help!