I tend to be an anti-justify guy, in print as well as on screen. On screen is more dangerous since you don’t have complete control over how it’s presented. Narrow columns can often create drastically uneven word spaces, especially if you don’t have hyphenation. 

A colleague asked me: 

... Do you feel you are in the majority on this? (anti-justification) ...

I answered: 
Depends on who you ask. I think most people don’t really care, but typographers tend to be an adamant bunch, and they seem to be pretty much 50–50 on justification. If type is set well, with good hyphenation, adequate column widths (55 to 65 characters, incl. spaces, per line), etc., justified is OK. Flush-left-ragged-right (FLRR) also needs to be set carefully, but it always has equal word spacing (providing double spaces haven’t popped up anywhere). Some will say that the shapes created on the right hand side of FLRR setting are distracting, but at least they are on the edge of the text block, not in the middle, where I believe uneven spaces are more distracting. Tests on readability, comprehension and retention have been inconclusive, so it ends up seeming to be mostly a matter of taste. 

Robin Kinross’s book on the subject – Unjustified Texts – is great. It seems to be out of print at the publisher’s: 
https://hyphenpress.co.uk/products/books/978-0-907259-17-6

But available here: 
https://www.amazon.com/Unjustified-Texts-Perspectives-Robin-Kinross/dp/0907259170/ref=sr_1_1?ie=UTF8&qid=1490180050&sr=8-1&keywords=unjustified+texts+kinross

A nice word-play title. The book is not only about justification though – other aspects of typography are also covered. I can recommend it highly.

I’d be happy to hear opinions on this. 

This one looks like a forced line break, not noticed in proofreading. I have quite a number of other examples, I bet readers do as well. 

Sometimes it’s not overly large word spaces, perhaps just unlucky alignment. Justification can exacerbate the problem and create so-called “rivers of white”, as in this sample. 

On web: good copywriting, no justify, turn off hyphens.

On 4/21/2017 at 6:54 PM, Peiran Tan said:

On web: good copywriting, no justify, turn off hyphens.

Why no hyphens?

Since most installed browsers support hyphenation, I do not see any reason to turn it off. Especially on smart phones it enables the reader to grasp more text per line. Thus the number of jumps to the next line and time spent on scrolling goes down. Readers may thus read faster and with more comfort. Therefore I think that hyphenation is of advantage to the reader, especially when text is set justified.

On 21/4/2017 at 6:54 PM, Peiran Tan said:

On web: good copywriting, no justify, turn off hyphens.

Good copywriting is always a good idea, not just on the web! 

2 hours ago, Ralf Herrmann said:

Why no hyphens?

45 minutes ago, Albert-Jan Pool said:

Therefore I think that hyphenation is of advantage to the reader, especially when text is set justified.

Hyphenation is a must for any justified text from well before Gutenberg (that’s one reason why ebook readers that force justified text without hyphenation are [insert expletive here]).

On the other hand, for ragged text, automatic hyphenation could, at times, produce unwanted or less than ideal results.