This is a good, albeit highly charitable, overview of Marcuse's outlook and philosophy.

To be slightly less charitable but more realistic, it is worth considering the current state of the Scandinavian countries and how they got there, compare with, say, the United States; and then re-examine Marcuse's views in that light.

As with Horkheimer's predictions and analysis in Traditional and Critical Theory and Eclipse of Reason, we can observe that the one who was lacking imagination was, in fact, Marcuse. It has been eminently possible to be comfortable yet politically potent; to imagine a better reality and make it so within existing systems. Not everywhere, but somewhere, a somewhere that more than anywhere else embraces a scientific (and therefore largely analytic) point of view (but not at the expense of building a good life).