I've got experience with Richard Photo Lab but none with Duggal. RPL's scanners do a great job with most scans, however they do better when given examples of how one's color and density should be prior to starting a scan. They offer a custom color service, that is not cheap, where they consult with clients to understand skin tone, density, and hue preferences. Start to finish the custom color service takes a few weeks to nail down but should be dialed in and smooth running once everything is agreed upon. I used to think the service was essentially creating a preset, but after visiting the lab (I'm in LA) and watching the scanners in action, what they're doing is essentially eye-balling a few of color match prints supplied by the client and scanning to match said prints.
Turn around time for the scans range from 2-5 days depending on service level chosen and production load of the lab. Not sure they still do E6 in house, should call and check. If you don't know the difference between the Fuji and Noritsu scans, you should research that before starting the service. There is a pretty big difference in image quality (neither superior, just different) and it's important to understand what one wants before committing.
