First of all, I know it’s developer beta 1. I’m aware it’s unfinished and I’m aware that there will, inevitably be bugs. I don’t need reminding.
I just wanted to point out that the Files app has some serious bugs at the moment. I’ve done several things which have caused it to hang (e.g. copying files by using the buttons.) but the most serious thing was data loss. I had a number of large files (4-12GB) on an externally connected ExFAT-formatted USB SSD. I was able to open and read them all just fine. After a few minutes, I received a connection error and afterwards, all the files were corrupted and only a megabyte or two in size. Morale of the story is that it’s probably not wise to use the files app with removable devices at the moment - at least for anything for which you don’t have a backup.
There are no issues with the drive and there was no physical disconnection
I’ve filed a bug report already and haven’t had a repeat issue since I formatted the drive as APFS.
Other than that it seems to be working quite well. A couple of issues connecting to SMB shares which hung the app but nothing major I’ve come across.