Readability of overlaid text on images

Text on images seems to be very popular these days, and it does look nice. However, it can be hard to control the legibility of the text. I have darkened the background, and added text-shadow, and it looks fine to me now, but others still say it's not that easy to read.

I was wondering what is the consensus on UX for said design style? Are visitors more compelled to read it?