I like that, in all but 3 of the magazines, the masthead is kept white. This means it's easy and simple to read, and blends with the cover image well.
In the 3 mastheads that have colour, it is used to connote something about the subject ('Gold' they won gold, the black stand out, like the boxer), or used to include house styles to make the magazine cover look more appealing.
The use of a main mastehead, with a subheading underneath is effective in that the masthead connotes the topic of the article, and the subheading explains it for those interested, both methods getting people interested in the article and so the magazine.
Placing parts of the image either in front or behind parts of the cover image blends the two together, as 3 of the magazines do, making the design less clean cut, but more applealing to the eye.