Comment by timw4mail

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)