[a]n A+ journal would typically be one of the best in its field or subfield in which to publish and would typically cover the entire field/subfield. Virtually all papers they publish will be of a very high quality. These are journals where most of the work is important (it will really shape the field) and where researchers boast about getting accepted. Acceptance rates would typically be low and the editorial board would be dominated by field leaders, including many from top institutions.
It gets even better. My wife, Akiko Tsuchiya , and one of her colleagues at Washington University edit this journal. I've published in it several times, under two previous editors and regularly review articles for them. It is very satisfying to give a critique of an article that leads to its improvement and eventual publication.
I can't publish in this journal myself any more, because my spouse edits it. Neither of us would be comfortable with me trying to submit my work there. I'm happy to work on the editorial board. While it would be nice to publish there, since it's the best journal in my field, my career has done fine.