The current Pulse clients have support for newer operating systems and meets additional certificate signing requirements from MS; is there a specific version you would like to compare? As with all software, the higher the version the more features available.
The command is the same, other than you are calling a different .msi file
Can you clarify what you mean on registry key to reset? Does the client-side changes guide, found at https://www.pulsesecure.net/techpubs/pulse-client/pulse-secure-client-desktop for each version answer the question you are looking for?