I currently use and am happy with LR4. I like the keyword ability to sort, and the image manipulation abilities seem just fine. Work flow is efficient.
I had a long discussion with the Canon representative who did not suffer from humility from either his own abilities or the Canon line of cameras and software.
He opined that DPP software was superior to all other processing software because it communicated directly with the digital files from Canon cameras in a proprietary. His argument was that importing through DPP (especially in raw) frequently obviated need for pp, and that lens tuning/correction could not be matched by third party software.
There is little argument that DPP will deliver beautiful files. On rare occasions I'll go to DPP with a file I'm having a hard time with in LR4/ACR, usually because of tricky skintones. Maybe as often as once a year...
The Canon guy you were talking to is the perfect blue-print salesman, one-eyed as you can get about the product, with persuasive lines yet perhaps somewhat lacking in knowledge of the true needs of photographers and the ways they process RAW files.
If DPP was a match for LR4 I think most Canon professionals could have caught on by now. As you know yourself, LR is workflow headquarters...there is nothing better if you have got a deadline chewing at your neck and there are a few hundred files to output before morning coffee.
DPP certainly has its place, but not as a tool for busy photographers working with large folders of image files. DPP certainly looks very pretty in the GUI department, but like so much Canon software, it's easy on the eye but behind the game in the performance stakes. The Canon Suite is a welcome inclusion for those on restricted budgets but it's not professional standard. EOS Utility anybody? Now there's a piece of Canon software just screaming out for a full redesign. It's barely changed since its first incarnation. Zoombrowser? I don't know a working photographer who actually uses it. Powerful programs such as PhotoMechanic or Breezebrowser Pro are the usual browser choices. Bridge has all the options but is a little slow.
DPP? Sorry Mr Canon salesman...I'm not convinced.