Went out for the first run today. Everything worked out well. I forgot to bring my temp gun, but the fan on the MMP never turned on, and the Neu stayed pretty cool as well. I was a little concerned the 5000mah 20C Turnigy hardcase packs wouldn't be enough, but they had plenty of punch and didn't get hot. The Badlands-style tires really bite in on grass, I traction rolled a few times before I learned how it handled. This was the first time I drove a buggy and I was impressed with how nimble they are.
The only issue I had was that the MMP has a suspected faulty BEC (you may have seen my posts in the Castle forum). Even with a 1500uF cap the SR300 receiver powered down momentarily a few times during the run. I think I'm going to send it in to Castle.