I just noticed some thing a little odd with one of the capacitors on an ESC.
The capacitor leg next to the negative wire has broken, I suspect that this happened over time through repeated plugging and unplugging of the battery causing the negative lead catching the top of the capacitor and put strain on the leg.
It's going to be easy enough to fix, but would have gone unnoticed had I not seen the capacitor move when I was looking over the battery connector.
I have been using HXT connectors in which the positive and negative connectors are housed in a common plastic surround. I think this naturally requires more force to plug and unplug and also pulls the ESC battery leads in together which transfers any of the leads movement onto the capacitors. I've decided to split all my remaining HTX leads.