Whats the use case? IF these are servers that need to be running all the time and/or are used in a buisness then vsphere is better. For the most part they are pretty much the same, workstation is more for testing on a development computer thats used for other things. ESXi, the hypervisor part of vsphere, is more for vms that need to run long term and that need more peformance then a level 2 hypervisor(workstation) can provide.
