Recently added a re-plated 1958 D-4 Fatboy to my collection. I'm holding off on using it as I don't want to harm the shiny new nickel finish, so I still use my 1960 F-4, but for a few differences in handle design they're the same razor. So far my favorite adjustables are the Merkur Progress long handle and Parker Variant (tied for first), with my Viking's Blade Emperor Augustus coming in second, Gillette Fatboy third and my PAA Ascensions tying with that.
My favorites are Gillette Fat Boy, Slim Adjustable and Super Adjustable. But since I have no experience with the others, my opinion isn't very objective
Ok, so I tried it and it's workable that way, and without detents, it's infinitely fine tunable. So, I'm only going to recommend that if you already have a single ring and you've never tried it as an adjustable: Try it.
I spent some very enjoyable time with a beautiful Slim. I learned to get BBS with every setting. This taught me so much. I have a debt of gratitude to the Slim. I had someone important enough to me that I had to gift it to them. But I am almost 100% SE and Injector anyway. But 3 years ago at Christmas my wife copped a Ming Shi 2000s as a stocking stuffer...Almost as a joke...But...that Ming Shi Adjustable is a fine razor and I believe it outshaves razors that cost 10xs as much. Bravo Ming Shi !! It won't replace my ER Lather Catcher or Auto Strop A1 or my injectors...but I would not want to not have it in my Shave Cave...a Veddy high quality piece!