This probably gets asked time and time again, with regards to the 3 main Gillette adjustable (Fatboy, Slim and super adjustable) are there major differences between the settings and aggressiveness of shaves given. I have used all 3 but aesthetically prefer Nickel plated so Slim and Fatboy. To me the Slim and Fatboy shave the same (this was about 6 months ago I last used one) and in that time I have gone back to basics with wet shaving using a simple 3 piece Ikon and have refined and got my technique, what I believe, to be perfect. Now I think I can throw an adjustable in the mix for what it's worth to see if I can get better shaves.
I believe some people think adjustables are a gimmick but are they really an improvement over a fixed head?
Any advice.
It all depends on how you use them, and what you personally need.
Adjustables allow you to alter the gap/blade configuration to suit different combinations. Not all blades are equal.
Obviously you can't do this with a fixed gap, and I find such razors usually show their best performance after some experimentation. The same thing will eventually happen with an adjustable, at which point it's a decision about whether to stick with particular blades and settings.
Some people like to vary the setting in their adjustables from pass to pass. I personally don't, unless I find I've got it set all wrong.
There is also the 3-piece Rockwell "adjustable" solution, which I find a good razor, and I'm a keen user of Mergress and Digress adjustables.
I'm not sure whether there are any open-comb adjustables a la Fatboy/Slim etc. (I expect someone will tell us), but I haven't got one; so if you want SB or OC options, it will probably have to be a 3-piece razor. Then there's the matter of cleaning adjustables, but that's another subject.
As for whether they're a gimmick, the Gillette stable have been about for a long while, they're superbly-made, people still want them, they do the job, and if anybody could come up with something similar but rather more affordable than the Barbaros/Rocnel offering, I think they'd sell well.