I've been using the North Face resistor[1] for about two years.

Pros:

- Sturdy and great quality

- A lot of space

- Comes with a charger

- Nice design

Cons

- Expensive

- I don't think it fits well under the seat when you take it with you on the plane. It uses a lot of space

[1] https://www.thenorthface.com/shop/resistor-charged-nf0a3kxj