Now that I have the "C" rating thing sorted out can someone shed some light on Deans plugs? They are rated for 50 amps (10C on a 2s 5000) Why do people continue to use them?

Don't worry about the rating on the Dean's plug. They're still widely used because in the real world, they don't melt or malfunction in any 1/10th applications. That being said, many racers prefer 4mm bullet plugs straight into the battery pack for a little less resistance but if you want a solution that you can't reverse polarity on, you can't go wrong with Dean's plugs.

It's either straight in, Dean's or Traxxas plugs. You won't go wrong with either as long as you pay attention with straight in.

I went with 4mm bullets but I see guys using deans in 1:8 and short course all the time. I just thought I was missing something.

Well, I think you might be missing one thing, when you see a C rating on a battery, that is simply referring to how much current it's capable of supplying, but that does NOT determine what will be drawn continuously. The MOTOR is what draws current, & how much it can draw will determine the load on the battery & the connector, & most motors, once past the peak load(from a dead stop), will usually only draw in the neighborhood of 25-30 amps at most. And much like the burst C rating on a battery, a Deans connector can handle a LOT of current if it's only in a burst.....

Some batteries have the leads attached inside of the package so having an attached connector is a must. The batteries with sockets don't need the connector on a pigtail, but I use one anyway as I do have batteries of both descriptions.

The only people that are melting deans ends are people running 6s Lipos and above. Those types of batteries it's challenging to get a deans end soldered on a 6s Lipo since the gauge wire is so huge. I would be scared...