I use DPP and love it.
I tried LR4.0 and didn't like it all that much for the following reasons.
Slow on my computer
Disk management
All of my processing came out dark for some reason.
I think LR saves edits to a separate file, instead of inside the raw file itself. So, there are multiple files for an edited raw. (I could be wrong on this one).
What was awesome about LR: Plugins. The fact that I could have a smugmug shortcut, flickr, facebook, etc. directly in LR and simply drop the edited raw into a gallery (created within LR as well) then publish was great. I miss that.
Most of my problems with LR comes from an older laptop. Limited space means that I am pretty active about archiving stuff that isn't necessary. I would most certainly benefit from an upgrade, but don't have the $$.
Other than that, LR changed my workflow too much, I didn't like it.