I've run Achtung with Savage Worlds, as the setting seems to fit a little better with SW, given its military focus. I had initially planned to use 7th, but the lengthy delay forced our hand and I didn't own 6th Edition CoC. Honestly, having played both systems, I would probably continue to use SW for Achtung, but that opinion may change if the Pulp rules (when they appear) look like they can handle the increased military/combat focus.