Hello Steven,
The difference lies in the installed sensor.

The G Pro Wireless uses the new HERO sensor from Logitech with 16,000 DPI.
The sensor in the G305 is still the "old" HERO sensor with 12,000 DPI.

The optical sensor is the heart of every gaming mouse.

You can find out more about the sensor here:
https://www.logitechg.com/de-ch...

The G Pro also has a (non-replaceable) battery, which you can recharge directly during use with the USB cable supplied. The G305 is battery powered. Also, the G305 does not support Powerplay, so wireless charging of the mouse with Logitech Powerplay technology is not possible (it does not have a rechargeable battery out of the box).

The Logitech G Pro Wireless has interchangeable side buttons (on both sides). You can customise them to your taste, 4 different replacement buttons are included. You can also customise the mouse to have no side buttons at all, or make it left or right handed (or both if you prefer).

The G Pro has a 3-stage optical LED DPI indicator on the back of the mouse. The G305 does not have an optical DPI indicator.

And yes, the mouse still looks different. Maybe you like one of the designs better.

tl;dr: The G305 is a wireless version of the "old" G Pro Wired mouse. The G Pro Wireless is a completely new revision of the G Pro series.

Greetings Dave

Thank you very much for the super detailed and informative answer!