Ctein makes a few observations:
- His conclusions relate to OS X only, which uses the wider Adobe RGB colour gamut, whereas Windows is restricted sRGB when printing. As a consequence Windows users need to stick with profiles.
- If using a profile, Perceptual rendering is better than Relative. Usually the "standard" advice is to try Relative first and switch to Perceptual if you do not like the result.
- His conclusions relate to the Epson 3880 and P800 printers which he used for the test. The outcome for other printers might be different.
- Printer managed colour is best, even with non Epson papers. In that instance, choosing the closest Epson equivalent paper works well enough.