I did 3 months on dexcom one.
I found the accuracy to be no different to libre. Had some great ones and some not so great ones.
They are bulkier than libre.
You have more choice on official placement of the sensor.
I liked the fact you could use reader AND app at the same time without any issues (start on reader and then the phone app knew about the sensor you just started).
the app itself was "basic" as in you couldn't log any info yourself like you can with libre (carbs, insulin, exercise and notes)
I found they needed to be overpatched more often than I do with libre but dexcom sent some to me for free when I had to get a replacement which were fab.
With libre 2 bring CGM now, that playing field has been levelled.
If you loose signal with decom you cant scan the sensor to get a read on your bg when you are back in signal range, you have to wait for it to reconnect where with libre 2 you can still scan.
I am on libre 2 now fulltime but that was due to what I was offered on prescription vs my own choice.
For me, if I had the choice myself, libre slightly comes out on top and only because of the app logging features as I use them a lot.
I miss the ease of using reader and phone together without any issues as sometimes just slipping the reader in my pocket was easier than grabbing my phone. Being able to disconnect and turn my phone off is something I miss too.
I can still use libre reader and phone together but I loose CGM function unless I use a 3rd party app (which has its own drawbacks with more signal loss issues).
Hope you get on better with tech this time around.