I can tell you about the 4 adjustables I own so…
The Emperor is a solid razor. It’s heavy and seems well built but it’s my least favorite of my group.
I have 2 vintage Gillettes. The Black Beauty, it’s similar to the Slim with a longer handle. It’s a very good razor. I have a 1960 Fatboy as well, this is an outstanding razor.
Oddly however the Merkur Progress (even with they silly tip on the handle) is my favorite of the 4. It took a few shaves to find my sweet spot and perfect blade for it (as with the others) but set a 4 with an Astra SP or German Wilky, the save is perfect.
As for adjusting “on the fly”. I can’t recommend that no matter which razor you choose. Start low and adjust up each time you shave until you find the sweet spot. The closeness my be lacking (or not) for the first few shaves but it worth it in the long term.
The Emperor is a solid razor. It’s heavy and seems well built but it’s my least favorite of my group.
I have 2 vintage Gillettes. The Black Beauty, it’s similar to the Slim with a longer handle. It’s a very good razor. I have a 1960 Fatboy as well, this is an outstanding razor.
Oddly however the Merkur Progress (even with they silly tip on the handle) is my favorite of the 4. It took a few shaves to find my sweet spot and perfect blade for it (as with the others) but set a 4 with an Astra SP or German Wilky, the save is perfect.
As for adjusting “on the fly”. I can’t recommend that no matter which razor you choose. Start low and adjust up each time you shave until you find the sweet spot. The closeness my be lacking (or not) for the first few shaves but it worth it in the long term.