ὁ τοιοῦτος ἐκράτησεν ἔτος α´. Psellos: Chronographia VII title
When Theodora 1's act was done, the reins of power were put in his hands, an old man unable to bear the motion of the imperial chariot; the horses at once carried him off, he increased the disorder, and retired from the race overwhelmed
[The adjective surprisingly seems to imply youth; perhaps "inexperienced" or "more recent", i.e. after Michael IV and V?]
nobicius. Anonymus Barensis 152
He was subservient to the palace officials (who chose him for the throne), in his stupidity and negligence he could not resist entrusting them with government, and was experienced in politics and military matters, but was an old man
πλεῖον δὲ τῷ γήρει τρυχόμενον. Attaleiates: History 52.16-23 / 39.16-40.4
Those who had rebelled against him called him 'the old man', and this is how he is still called today
He was a good man (as were Anonymi 7011 who promoted him), but with no idea at all of how to govern, being driven rather than driving himself, living the life of a private citizen and leaving the government to others
Psellos Keroularios 360
He did not (to put it generously) have a good grasp of the science of governance
Originated from Byzantium, but was naturally unsuited to handle such great leadership in government both because of physical sloth and simplemindedness, and because of the length of time which had stretched out in his life
Hailed from Constantinople, a simple man who had only been involved with military matters and knew nothing else, having already entered old age, and whose disinterest in public affairs suited some people, as the poet Archilochos says
He was not the kind of man to rule but rather one to be ruled and led [unnamed]; he was approaching the high season of years verging on old age and his hair was completely grey
After his proclamation as emperor the ancient Michael 6 seemed to be most generous to the members of the senate and to the popular multitude, even beyond what was proper
The soldiers were plunged into despair when they saw that he was most generous to others, but to them he did not demonstrate goodwill even in words, but nevertheless they held back from any kind of rebellion, but planned to make a second attempt