I've been using the manufacturer profile to print on Lumière Brilliant RC with a Pixma Pro 100, and the results have been mostly fine... admittedly I print mostly B&W, but the few colour prints I'd done looked ok.
Then I printed a photo of a peach. Below is the manufacturer profile vs a custom spyder4print version. The colour has been distorted again by re-photographing with my phone, but you can see how enormous the difference is. Surprising, no?