I also decided to shoot some thickness comparison photos:

From back to front:

• your standard mechanical keyboard
• low-profile mechanical keyboard from a shop
• Dorsch 48k
• Flounder

And a close-up of comparison with a standard mechanical keyboard:

So yeah, I think there is a definite improvement.

Why do I need a low-profile keyboard, though? It's simple. Ergonomics. You really don't want the heels of your hands to be pressing down on the table, leading to RSI, CTS or a number of other TLAs. With a low enough profile, your hands can just lie flat on the table without any special wrist rests or other contraptions, and be flat enough that it's the palms that bear the stress and not the heels.