It seemed like someone on the VMware forums had a similar issue, yet it wasn't resolved. https://communities.vmware.com/thread/574921 I can just suggest the most common solution of "reconfigure it and see if that helps".
@LAH3385 might be good to start a thread and try to determine what your needs are before going down the path of technology. By the time you were asking this question, you were already in pretty deep assuming certain products, product categories and platform HA. We should start with a business needs analysis, use that to set goals and then use the goals to select technology approaches.
XenServer supports SD Card installs. Not sure about Xen
XS is just a packaging of Xen. So anything XS supports, Xen has to have supported. Xen is completely flexible and can be used anyway that you want, it itself doesn't have the same concept of "supported" like XS does.