What happened to save path autocompletion?

[bruman]

Until 4.5 or 4.4. it was all fine, you type: "Fa" and auto complete shows you all folders that start with "Fa": "Fallout, Fault, Fauchi". Then this was just gone. Now you have to press CTRL+SPACE, the hotkey, never mentioned anywhere but on forums, you have to find it out and then get the now disabled by default function back. Why? What happened? Am i taking the crazy pills here? It was very convinient. Why would devs disable it by default? How can i turn it back by default, aside by rolling back to older versions?