The Pro has a nice backlight that is useful when reading at night. The only downside is the lack of a USB-C port, so you have to use their magnetic dongle to charge. Also, if you want one, I recommend buying from the official site to avoid getting one with the firmware locked (there may be a way to unlock it, but I'm not sure). Lastly, look at the competition: I'm happy with my X4 Pro, but there are a couple of others with different feature sets that are still compatible with Crosspoint and may be of interest if you want to use it for more than just reading.

Justs a heads up, people are comparing with the X4 and not the X4 classic. The classic is a brand new one released today, and it replaces the X4 on the official store. It doesn't have a USB connector either, so it's all pogo connectors now

For the Pro, you will want a 3d-printed dock, or a really thin USB-C cable to use with the pogo pin dongle.