There is a family resemblance to my Aristocrat 66 and Rocket HD500 as they are similar in weight. I loaded up with a new Feather, Pacific Shaving Co. pre-shave, and Cella, bowl lathered. What setting to use? After humming and hawing I set it to 4 thinking this would be similar to the HD. First pass was amazingly smooth. At first I thought I had the angle wrong because there was so little noise. Second and third passes went with no drama - not even a nick. I felt with the HD500 that I had to be more careful than with the Fatboy. Fatboy head seems slightly harder to maneuver under nose, but not too bad. I'm hoping not to like this razor, since I passed on a reasonably priced, replated one on eBay. Hmm. Under my neck and chin was not quite as smooth, but that was probably down to me not paying enough attention to those areas in my eagerness. Where the Fatboy really excelled was at the edge of my chin. This is usually a danger zone with either the Aristocrat or with the HD500, but I felt I had complete freedom to use any angle with the Fatboy, and I had zero irritation. Only one shave, but colour me impressed.
Because I shaved at mid-day the day before, I did not have a super amount of growth. I was going to leave the fatboy on 4, but I asked the dog and she said "drop it down to 3", at least I think that's what I think she said. Same process as before. I did still need three passes, which surprised me. I also paid more attention to my neck. End result was smooth and comfortable. I think I'd have to really do something dumb to cut myself with this razor. Perhaps next I'll go beyond 4, but I'm not sure I'd ever need to in truth.
Same regime as before. This time I cranked to fatboy up to 6. I did notice the agressiveness. It felt more like my other Gillette TTOs and demanded a bit more attention. My earlier hubris about not being able to cut myself was repaid with a slight weeper that closed before the shave was done. I also reduced it to 3 for the final ATG pass. Having said that the resulting shave did not seem any different to before. I needed to touch up my neck but the fatboy's manners around my chin were still impeccable. I'm not sure what I gained by cranking up to 6. The shave didn't seem any closer than with 4, but then again, I still didn't get any irritation.
Went back to 4 for all 3 passes. Still had some trouble under neck and chin. I probably overdid a bit so got some minor irritation. I may take a break from the fatboy for a day or so.
Back to Aristocrat #66. Nice, comfortable shave, a bit on the mild side.
Set 3, dropped it to 1 for next two passes. I think this blade is at it's end, so not the greatest shave.
That's more like it- new Feather blade and tried a different soap, Body Shop Macca/Aloe. Great shave on 4. Had 2 days growth, so plenty for the razor to work with.
For me, this razor on 4 is a stellar performer and a great tool. I'm not sure I'd ever feel the need to adjust it, but it's nice to have options. From my limited experience with vintage Gillettes, I think there are more similarities than differences. With each model, it's a matter of remembering it's tendencies and adjusting to it. I wound't mind trying a Slim at some point, but I do see the appeal of the Fatboy. My slight reservation is that their collector status has pushed prices go to a point where they are no longer bargains like many other vintage Gillettes. I'm tempted to look for a "user" Fatboy, like my Aristocrat which has the plating missing from the bottom of it.
Thanks to the OP and those in the chain for the chance to try this fine razor.