I've had the X3 for a month and I love it. It's so small I forget it's in my pocket and have almost washed it a couple times. I'm working on custom firmware for it, so I ordered an X4 when they had the 20% off sale to test on there too.

As a crazy person with both, I have mixed feelings between them.

In favor of the X3:

- Crisper text

- Whiter display

- Slightly better battery life

- Top-mounted power button (subjective)

In favor of the X4:

- Larger display

- Plain USB-C charging

- Slightly better custom firmware support

- Backward and forward button on the same side (subjective)

link the custom firmware!