I've used both in production. The Xangati appliance is simple to setup and gives you good graphing information. The Stratsphere appliance is much more detailed (which is both good and bad) good becuase I want more detail, bad becuase it requires an Agent to get that detail. But really they are both good products and I commend you for your forward thinking and making sure you get a product that allows you to keep tabs on what is happening in your environment. A lot of deployments fail as they scale becuase they have no idea what good performance is and when they aren't meeting an SLA on that kind of performance in their VDI environments.
Gunnar
