Accuracy is the same as long as you follow the setup guide. The V3.1 is the latest with a shielded sensor wire. The V3's are the same electronics wise but do not have the shielded cables.
On machines like the Creality printers the weight savings don't make a difference. The main reason for releasing the Mini was for machines with compact hotends like the Wanhao D6 or for people making their own mounts and wanted a smaller sensor.