We have been using the Tegile HA2100EP since October of 2011. We currently have a 200+ desktop production environment for our students running everything from linux to server 2012 and all the windows clients.. The box has performed better than our equallogic at all tests and scenarios we have thrown at it. Different vendors compute dedup and compression savings different ways so here is a direct snip from our production box, so for 1.13TB of real world data we are only using 424 Gigs on the disks..
Creating replicas was at about 15 minutes on the Dell, now ~5 minutes for a ~40 gig image.
Their tech support has been responsive when needed, we just purchased a second controller and JBOD to use for student lab storage and imaging.