An article that at a high level compares VDI to SBC from an ROI perspective. Always very important to do in any desktop virtualization project. The author works for a VMware / Cisco partner.

 As with every key virtualization platform decision, I recommend taking a strategic approach. Start with an ROI analysis to first evaluate the economics of moving to a hosted desktop architecture whether VDI or SBC, but supplement it with an evaluation showing how the new technology will impact corporate objectives such as responsiveness, employee empowerment, disaster recovery, green initiatives, etc.

While industry analysts often contend that VDI does not offer a positive ROI, I have found that generally it does. Additionally, there may be benefits in terms of improved security, time to market and user productivity that warrant a move to hosted desktops even without a compelling ROI. A law firm with which I worked, for example, estimated increased billings of $1.6 M per year by enabling partners to bill more hours through remote desktop capabilities – an amount that easily overshadowed the projected savings.

Assuming the ROI and other benefits warrant a move away from traditional physical desktops, the best architecture can then be determined based upon environmental conditions and staff experience/expertise. An organization, for example, with a significant deployment of XenApp, even if used primarily for application delivery, might find it an easy transition to implement XenApp as an enterprise desktop replacement solution without requiring a significant investment in IT staff training or back-end infrastructure. A highly virtualized organization, on the other hand, may find that it makes more sense to extend its virtualized data center down to the desktop leveraging the existing infrastructure, licensing, management console and staff expertise.

Source: http://www.bythebell.com/2010/12/vdi-vs-sbc-a-roi-case-study.html