Like Ty said, make sure they are of good quality. Stay away from connectors that don't use gold plated ends. Also, make sure you use some way to keep them together under vibration. I use 3/8" shink tube for those connections that I don't need to take apart for tranportation and J-tec keepers for those that do. I've used Cermark, JR and custom harnesses from RadicalRC, none have given me an ounce of trouble.

......Mark