I had a mixture of IP67 and IP68 pixels. The IP67 definitely had more problems -- water was the biggest issue.
I had problems with my SSCs as well, the cat5 connections suffered shorts and corrosion. I got a can of CorrosionX after the show and sprayed it on some items. It was a thick bubbly slime, and I don't feel comfortable about putting it on my electronics. I purchased the HD variety for marine use... that was likely a mistake.
I've decided to do a few things for the upcoming show: lift the SSCs off the ground, and position the connections so that water runs down over the sealed side of the pigtail connector (not into the unsealed side). For new SSCs that I build I will also have the input AND output wires run through the same end cap so that the drill holes face down. The other action is to use press n seal over all exposed cat5 connections.