Well, the fan in my MMM finally gave in. I also noticed that one blade on the fan broke off...possibly blocking the fan and burning it out. I'm not going to bother getting a replacement fan from Castle since it seems like these fans are about as durable as 3racing fans. I'll try the Novak fan and if that dies too I'm going to mod the case to fit a Muchmore fan. I've been running the Muchmore fans on my 4 MM's and have never had a failure.
On the plus side, I ran my MMM on 6s again today and it's still going strong. My Savage will easily backflip back onto it's wheels on pavement.

I tried to do some GPS speed runs, but my Savage is just too unstable over 50mph.