[whpalmer4]

OmniPlan keeps track of resource utilization and availability, of course. Resources can be shared between separate projects. You do have to take some care in how you set up the resources or it will be a case of "garbage in, garbage out" in short order.

Currently, you can get reports showing you all the tasks assigned to all the resources, and the Gantt chart has an option to show you the utilization fraction over time of any given collection of resources. It does not give you a global overview of the utilization of the shared resources in other projects; you can see that Joe is allocated 50% time to the current project, and that he's got work to do in that 50% time until the cows come home, but you can't see that his other 50% is completely unassigned.

If you have access to a Mac, my recommendation would be to download the 2 week free trial of OmniPlan for Mac and see if it is to your liking. It will give you a somewhat more powerful set of tools than the iPad edition, and you can get an idea as to whether the OmniPlan model will allow you to do what you need without having to figure out if your difficulties are due to the underlying model or simply the iPad application. If you can't do what you want with the Mac edition, you won't be able to do it with the iPad either. If, on the other hand, you find OmniPlan for the Mac to be compatible with your wishes, you could go ahead and buy the iPad application. You would have the entire 30 day guarantee period to evaluate the iPad app to see if it also meets your needs.

It is important to note that there is currently no linkage between OmniPlan and OmniFocus, though at one point there was work underway to provide such a linkage. It's important not to buy expecting that linkage to be present at any specific time, because there's no way of knowing when or even if it will make an appearance, and Omni is typically very reluctant to discuss dates unless the feature being discussed is virtually complete.