During the last VMUG there were several people who seemed to be using VMWare's desktop solution. Citrix and a few others also have one, but from what I've seen VMWare's is certainly near or at the top of the available solutions. Our desktop guys here are looking at both VMWare and Citrix and from talking to them they have VMWare higher in ranking so far through testing.
I personally have designed and deployed serveral VDI deployments ranging from fifty seats to serveral thousand
If you found this or any other answer useful please consider the use of the Helpful or correct buttons to award points
Tom Howarth VCP / vExpert
VMware Communities User Moderator
Contributing author for the upcoming book "[VMware vSphere and Virtual Infrastructure Security: Securing ESX and the Virtual Environment|http://my.safaribooksonline.com/9780136083214]”. Currently available on roughcuts
The 3 biggest players for virtualization solution is VMware View, Citrix Xen Desktop and Microsoft MDOP. As far as I know, I've been using both VMware and Citrix and I could say VMware View and NetApp NFS gears works great due to the technologies and software tools that makes your life easily and thin provision and deduplication with Linked Clones and Composers along with Rapid Clone Utility 2.0 would make your VDI experience the best. Even though Citrix is pretty decent with Xen Desktop but unless you don't have VMware ESX on board, then using Xen Desktop is fine if you're all Citrix shops and matter of fact I would have to deploy another Xen Desktop for upcoming client that's going to be fun And MS MDOP is fairly new and they really dont' have any connection broker solution yet but using virtual PC 2005 technology and Hyper_V and App_V to make it into a single MDOP solution for Software Assurance customers which is really cheap about $7/per user.
For consulting perspective, I would use VMware View and other storage vendors anytime due to performance, flexiblity and scalability but you can try out Citrix if you wish.
If you found this information useful, please consider awarding points for "Correct" or "Helpful". Thanks!!!
VMware vExpert 2009
iGeek Systems Inc.
VMware, Citrix, Microsoft Consultant