Windows 7 Ultimate 64-bit host, Fedora 22 (4.0.4-301.fc22.x86_64) guest. VMware Workstation 11.1
In a VM with no snapshots, I can execute "dd if=/dev/zero of=emptyfile", and my single VMDK file doesn't significantly (compared to amount of "space" taken from guest's perspective) grow.
In a VM with a snapshot, if I execute the same command, my VMDK file grows approximately 1:1.
Apparently VMware Workstation 11.1 is smart enough to save space when writing some unit size filled with 0's, but this feature isn't used when a snapshot is involved.
Note, I am NOT talking about compacting the disk in the guest, just writing out the zeros in the host.