The worry I have with Martz is that he is inflexible.
It didn't seem like he ran with what was given to him. He had an idea for a spread offense with a nimble, pass-catching back that was, IMO, a deeper version of the Pats 2003/4 system (almost a split-back WCO that uses the back 2/3 of the field).
When his playmakers got older (Bruce, Holt, Faulk) or went their own way (Hakim), he still tried to keep the same offense. He tried to plug a 5/7 step drop deep ball offense in with a porous offensive line and a glue-mitted QB with Carr's Disease. He now has a POWER running back now in Stephen Jackson, who is underutilized. If I'm him, I switch to a traditional offense, run screens until the blitzing stops, and use the fact that even though Holt and Bruce may have lost a little bit, they're still smart players. Run timed routes, 3/5 drops, play-action. Feed off what's there.
I also think Martz outcoaches himself. He'll run 75% passes one week, 75% runs the next, just to show he can and will do it (even though he's not winning). And the defense needs work. They're almost looking like the Browns: "VH1 Where Are They Now: The Past Ten Years of Cleveland Draft Selections."