ESP8266 D1 mini Pro 16M or 4M flash ?

[Rampler]

Hi guys,
i have some ESP8266 D1 mini Pro with 16Mbyte.
In the past a flashed always the ESP8266_4M1M bins.
In the newest version i saw this ESP_Easy_mega-20191122_normal_ESP8266_16M.bin.

What is the advantage of this ?
Can i use the 16Myte Version, without loosing the configuration ?
Does anybody have experience with that ?
What kind of storage we are talking, RAM or ROM ?

[TD-er]

I do strongly advice not to use it.
It is a lot slower (SPIFFS is really slow on "large" volumes)
You will also loose all stored data, since the existing SPIFFS will be removed and overwritten with the new layout.