I'm with you in the "feeling cheated" category.
That being said, I am in the smallest of small business markets, but the benefits of virtualization have been tremendous for them. The biggest client runs two esxi servers (and numerous desktops). I can only describe my use of esxi as "ghettoVMware" (with apologies to Willam Lam). Nobody in my client base has needed anything more than the free esxi hypervisor, and some ingenuity (like William's) and general sysadmin skills.
My gripe is not about not being able to access the hardware version 10 features, it's how the vm's become unmanageable if they get upgraded.
There are no meaningful benefits for my clients to have all those features, so the cost of acquiring them is a complete waste, except that we may end up painted into a corner. We could end up with a system where we can't manage a VM, and we can't license our way out of the problem either, apparently.
If I understand all that I've read (which is doubtful), even if we license a vCenter whatever (if that's what we need to get the "vSphere web client"), we won't actually be able to manage the esxi 5.5 host with it -- we'd have to do some downtime/migration/rebuild activity to bring them into the licensed whatever.
There is a variant of Hanlon's Razor at play here -- "Never attribute to malice that which is adequately explained by stupidity". At first it just seemed stupid. It's now been more than a year, and a second "point release" of esxi (5.1 -> 5.5) without a change, despite some extensive commentary and requests from the community, so stupidity is losing its explanatory power.
Although, VMware is getting to be more and more like Microsoft/Oracle et al. so, perhaps it is just stupidity. PDF available here.
In any event, the situation pushes this extensive user of vmware products to look at other, less dangerous tools.
