The major difference is that HTTP is a standard (i.e. low port number) protocol, while QVP isn't. In many cases QVP cannot be used straightaway because of firewall blocking. That's when Tunneling (between QVWS/IIS and QVS) comes into play. Otherwise you wouldn't be able to connect a Desktop or a Plugin from inside a DMZ to a QlikView server (QVS).
IMHO it's not a matter of what is best, more of what is doable.
Peter.
PS Better not select your preferred QlikView client solely on what protocol it uses. Clients have inherent qualities that surpass the pro/cons of protocols.
