I know there were some issues in earlier service packs with using the re-directs from the GUI, but I believe all those issues have been fixed. I have also done numerous duplicate restores, and typically also use the settings in the "PFILE" as it was just more convenient (Once one gets used to the syntax). But there are some new features for cross server restore (like cross instance restore) that is now available, and with that the PFILE settings won't work (RMAN only uses those settings with the "duplicate" command and not restore) so the redirect from the GUI is the only option at that point. With that in mind, I do know that there were a number of improvements on this ability.
Ernst F. Graeler
Senior Engineer III