There is some interesting work carried out by people like Philippe Aghion and Peter Howitt. Our concern is with what we see as the main trend in mainstream growth economics. This is in stark contrast to the bold proclamations made by some of its practitioners. Second, in some contributions to NGT you find attempts to come to grips with increasing returns that are internal to the firm. However, a firm that has become a monopoly because of that is possibly endangered by technical progress.
Some authors try to deal with monopolistic competition.
As to Brent McClintock's observations, here are some additions to Neri's reply. There is recently a stream of non-neoclassical growth models, all of which are 'endogenous' growth models. What is needed is a theory of investment. In the NGMs we analysed in our paper there is no such thing as a theory of investment. Not convincing at all, in my opinion.