[xenoscopic]

The benchmarks will likely be highly dependent on your use case, but SSHFS-style virtual filesystems (specifically those backed by FUSE) typically have significantly lower performance than something like an APFS/ext4/NTFS filesystem that Mutagen could target with synchronization.

All of your readdir()/stat()/open()/read()-style calls will suffer significantly on virtual filesystems, and unfortunately these get hit a lot by things like IDEs (e.g. when indexing code), compilers, and dynamic language runtimes (especially PHP).

No tool is at fault in this chain, of course, it's a hard problem. Mutagen is able to offer better performance by being a little less dynamic and creating "real" copies of all the files on a more persistent filesystem.