[aasasd]

I recommend http://practicaltypography.com, though it won't answer your question (iirc).

By ‘slim’ fonts, do you mean lighter lines? If so, afaik it's not a matter of prescriptive typography, and in addition, heaviness may vary with the font. For headings and short inscriptions, light fonts are alright (personally I often outright prefer them for headings), but for body text, you should check legibility of the chosen font on non-hidpi displays, and preferably ask someone with older and more tired eyes—as light fonts tend to cause strain for people with worse eyesight. Generally, of course, the ‘regular’ weight is the recommended one, since it's tailored for setting main text in the first place. The current fashion of using light fonts is brought about by graphic designers, not typesetters.

If you mean condensed fonts instead, those are only suited for short runs of text, since the lines become too dense.

[vtesucks]

I mean slender, less width. The latter. I saw that in the Mozilla post about goodbye edgehtml, the headline was in wide font.

[aasasd]

Ah, it seems Zilla Slab is indeed rather wide, though not as spaced-apart as e.g. Verdana, partly due to the slabs (which are an idiosyncratic choice for body text).

In my experience, wide fonts such as Verdana can be tiring in long texts, as the eye has to move more to consume the same words. However, in the case of Zilla, the letters are still close together, so overall the font is barely wider than more traditional serif ones. Note that it's also very well kerned and there are no irregularities in the type. So, the challenge would be to find a wide font that doesn't put letters too far apart and has good kerning. (Zilla itself is free, btw, like other Mozilla fonts, but again slabs are peculiar―it might remind too much of Mozilla sites if used in headings, but may be ok in body text.)

On the other side of the scale, narrower fonts are also ok until a certain point, where they become too dense and are suited only for short inscriptions.

Basically, there's an optimal width, and that's what most fonts use. Large deviations are risky, and you need to make sure that the chosen font works well in other aspects―'blackness' and kerning―or the reading experience will begin to fall apart.

Note that headings are very forgiving in regard to font experimentation, compared to body text―as the reader will glance over them pretty briefly.