We're talking about piloting VDI here, but the more research I do, the more it seems like it would make more sense just to upgrade and expand our TS (RDS) environment. I feel like you can pull off more sessions per core on RDS than on any VDI solution I've looked at. Is this the case?
Is there a decision matrix anywhere describing the benefits of using full virtualized desktops over using a remote desktop farm?
We need good video performance for clinical imaging - will this work better on one infrastructure or the other?
(Does this question have a specific enough answer for it to be on SF? Regardless, I feel like having this here will be helpful for someone in the future...)
Well I don't think there is any question that an RDP thin client solution is a more efficient use of raw resources.
The question to go full VDI is really one of security, user and resource isolation, and fault tolerance.
The benefits of VDI are related to providing a "machine" that is specific to each user. It has many of the same shortcomings and advantages of running individual desktops except that in a VDI solution you can limit physical access and better enforce data security than in a desktop model. Similarly, centralizing resources lets you deal with a smaller tighter networking topology and lets you utilize software at a higher level for doing monitoring of resources, backing up of virtual images / snapshotting and other tasks that are more complicated when distributed over an enterprise network.
So the question really is, do your users need isolated desktop environments, or can they run applications in a shared instance. If there is uniformity in your user base, work load is minimal, and the afore mentioned reasons are not terribly important than a straight thin client rds environment is the clear winner, especially from a management perspective. For the most part straight RDS is just simpler to deal with.
In addition to MattyB's answer, make sure you look into your peripherals before making a decision. Using RDS definitely provides higher user density in most cases in addition to cost savings (no VDA license!), but can be lacking in driver support. USB scanners and other devices often prevent organizations from using RDS strategies.