When I do speak to support, they keep confusing esxi with esx, and ask me to do things that cannot be done on esxi. I've also been studying on if I should run esx or esxi. For the way we deploy and the lightweight nature of esxi it makes more sense, and I believe its the proper model. They still need to develop a proper CLI/SDK or some way to get into the boxes better in a controlled manner without using the "unsupported" login method that support always asks you to do. That method requires console access which we don't have on lots of our hosts.
So far we have 2 hosts upgraded, and quite a few to do somehow or other. I'll keep plugging away.
Vmware support is very good, and responsive, good company to deal with, and great technology. They just haven't figured out the upgrades.