Don't have a Libre3 so I can't speak from personal experience, but there are some benefits and possibly some drawbacks.What is the benefit of the 3 then?!! Weird!
It is smaller and apparently uses less waste on the packaging.
With my Libre 2 the sensor keeps information for 8 hours and with my app (which is still the older Libre2 app), if I don't perform an NFC scan at least every 8 hours, then phone and my LibreView website will lose any information older than 8 hours. The Libre 3 sensor is supposed to keep information the information for the full 14 days and uploads as long as bluetooth and internet access is available.
However I have read several reports that say that you can not perform a manual NFC scan with the libre 3, so if bluetooth stops working, you can't tell what your blood sugar is. Since in my experience bluetooth is a lot less reliable than NFC that does concern me, particularly because Abbotts Libre 2 app does not seem to handle bluetooth as well as other apps. (The Libre3 isn't available on NHS prescription yet, so at least I won't be forced to use it).
Also reliability may be an issue and Abbott have had to recall some libre 3 sensors in the US because of inaccurate readings.
They don't seem to have spent much effort in improving the Libre3 app.