To start of, I love them both they are really awesome portable chargers, correct me if I’m wrong about any of this.
Let’s start with size, the 5000 is pretty thick and tall, but the 10000 is obviously much wider but more thin and smaller.
Next battery, the 10000 has double the amount of battery that the 5000 has, the 10000 can charge a smartphone about 3 times.
Their input is the same, I’m pretty sure that the 10000’s output is faster,
They both have one input and one output.
All in all I love them both, but in my opinion the 10000 is much better, but chose what’s right for you.