The original unix filesystem, designed by Ken Thomson, did not support symbolic links. Filenames were limited to 14 characters.
And it did not control fragmentation. We had to periodically defragment our filesystems by copying them to tape and reloading back on a fresh filesystem. And on our 3B2, I had to unload a 25 MB disk to diskettes to defrag. This was not my favorite job.
It really was designed in an era of tiny (by today's standards) disks and it didn't scale up to larger disks (larger = about 100 MB or so). It was comparable to FAT-16 or something except that FAT-16 has an in-place defragmenter.
The BSD filesystem, designed by Kirk Mckusick, addressed all of those issues and it was a big step forward. It really took over very quickly.
Also it seemed to be more robust. It seems like we lost fewer filesystems with the BSD design...and not just because of the backup superblocks.
So, yes, I noticed a few differences.