Monday Morning Conversation: D2D or VTL for Backups?

So I thought I'd start something new here and begin posting short thoughts and a question and get a feel for where everyone else is on the topics.  So today we'll start with Disk to Disk (D2D) backups or VTLs?

Over the past few months I've had the chance to work with both of these types of products.  I like Data Domain's D2D solution with data dedupe capabilities for the small to medium size businesses and I like the HDS/Diligent solution for the large businesses. 

My preference would be to use a plain D2D solution (CIFS/NFS Share) with data dedupe capabilities because its simple.  And when I say simple, I mean that you can have two Data Domain boxes setup within 20 minutes ready to accept backups and replicating between each other simple.  When you start throwing VTL in the mix, things start to get complicated.  Without HDS behind Diligent, I don't know that I would use that product because of the erector set it can become.  With HDS though, you get a single package and it works well.

So what do you guys think?  What have you seen out there that works?  Which would you prefer?