One caveat: snapshots created by ESXi
If you use snapshots in sesparse format you must merge them to the basedisk BEFORE you move over.
If you use snapshots in delta format you can use them in Workstation but not in writeable mode. Means you need to add another snapshot and then the way back to ESXi is closed.

The vmdk format used by ESXi itself "createType = VMFS" can be used inside Workstation when you redefine "createType" VMFS to "createType = monolithicFlat"
Read my VMDK-handbook for more on this.

Ulli