This is not entirely true.
To answer the easy one first. Yes EPO agent is free with vrops. Before you go and through it on to all your vms or servers (yes it will moniter physical servers) you may need to re architect your installation of vrops as it adds a lot more data to it so will need more space and processing power.
EOPS can be used in advanced edition as well and not just enterprise. The version of vrops will determine what you can collect. in short advanced will collect OS based stats with one exception (may be more but cant think of them) they will also collect the vsphere specific application data for example vcenter components cpu usage if you install the EPO agent on a vcenter. Install it on VRA and get those stats as well and so on.
Enterprise edition will allow you to collect application based stats (if the management Pack is installed) eg SQL, AD, SAP, Exchange and so on
Again be careful and dont just install it. There are alot of things that you need to take into account. If you want to know create a seperate post and i will type something up with my experiences.
