Plutarch, writing in the first century AD was mostly admiring and, to be fair, he was quoting someone else on Demosthenes' lack of brevity:
"And the same philosopher tells us that Polyeuctus the Sphettian, one of the political leaders of that time at Athens, declared that Demosthenes was the greatest orator, but Phocion the most influential speaker; since he expressed most sense in fewest words. Indeed, we are told that even Demosthenes himself, whenever Phocion mounted the bema to reply to him, would say to his intimates: "Here comes the chopper of my speeches."
"Just think. The instant this court rises, each of you will walk home, one quicker, another more leisurely, not anxious, not glancing behind him, not fearing whether he is going to run up against a friend or an enemy, a big man or a little one, a strong man or a weak one, or anything of that sort. And why ? Because in his heart he knows, and is confident, and has learned to trust the State, that no one shall seize or insult or strike him. That sense of security, then, with which you walk the streets — will you not guarantee it to me before you set off home?...
...For if you would only examine and consider the question, what it is that gives you who serve on juries such power and authority in all state-affairs, whether the State empanels two hundred of you or a thousand or any other number, you would find that it is not that you alone of the citizens are drawn up under arms, not that your physical powers are at their best and strongest, not that you are in the earliest prime of manhood ; it is due to no cause of that sort but simply to the strength of the laws. And what is the strength of the laws ? If one of you is wronged and cries aloud, will the laws run up and be at his side to assist him ? No; they are only written texts and incapable of such action. Wherein then resides their power? In yourselves, if only you support them and make them all-powerful to help him who needs them. So the laws are strong through you and you through the laws. Therefore you must help them as readily as any man would help himself if wronged ; you must consider that you share in the wrongs done to the laws, by whomsoever they are found to be committed ; and no excuse — neither public services, nor pity, nor personal influence, nor forensic skill, nor anything else — must be devised whereby anyone who has transgressed the laws shall escape punishment."