From the text of the Virtue: "You are at least (25 – Int) years old, and must have scores of at least 5 in Latin and Artes Liberales."
Just noticed this little oddity, has anyone else noticed it? This virtue almost pays you to be less smart... The tradeoff is that as a Magus who has this virtue, you need a LR as soon as you gauntlet, if not before. A less intelligent MiA gets more experience points, and can spend those experience points on Academic Abilities. This is actually gold for a Magus character. And if they do any rituals at all, having more XPs to put into Artes Liberales and Philosophae are just sauce for the goose, so to speak. Not sure it's broken, but it is interesting, nonetheless.
I think the intent is a) for Companion characters, it pays to be younger. Due to the time requirements of Magister, most magi are likely to not partake in it (especially not without the Gentle Gift). Also, I believe Companions can start at any age, so it's not like you're getting more for less. As for Magi, the book allows magi to start at older ages, so it's not a glaring loophole.
(IMS, I wouldn't allow a Magus to take this Virtue without being 10-INT years past Gauntlet... Theory being is that it takes some hard scholastic achievement to get this in the medieval world.)
It isn't "better" because the rules say "you are at least" not "you are" ... there is no mechanical reason you couldn't make a starting Magister in Artibus with an Int +5 who is 35 years old... just as there is no mechanical reason you couldn't make a magus who is 107 and 85 years past their Gauntlet.
OTOH, if there is a guideline in your saga that says your magus is fresh out of Gauntlet and no character may be more then 25 years old, then the rules for Magister in Artibus don't change that guideline. All it would mean is that to make a Magister in Artibus in that saga the character must have a minimum of Int +0 to be able to make a character allowable by both the virtue and the saga guidelines.
The +3 is at least 22 years old. The -3 is at least 28. I see no advantage for the second, as the first has far more options for CharGen and what they do with it. The only diff is that the second must be older - hardly an advantage.
Since both are, at this point, academicians, they can both spend later xp on Academic Abilities - again, no advantage there.
(In fact, since the rules state that it is "rare" for apprentices to be taken over 20 years old (p 106), smarter magi make more sense to then be inducted into The Order. Altho' the rules don't say so in so many words, it would be hard to imagine being apprenticed much before the MA period is completed, altho' something overlapping might possibly be arranged in the very last years given that Latin is no longer a necessity and the apprentice is more an "adult" than many.)
Not at all sure what you're seeing...
Which is why, imo, "Hermetic Age" is a better regulator for power for starting magi characters in Sagas than actual age (altho' both can play a part).
What age did people start University education? My guess is that you could start earlier than 17 years old, as everything seems to start at a much younger age in medieval times (marriage, manhood, monastic training, etc).
Afaik one could start Uni when a) they had an adequate mastery of the basics (i.e. Latin and writing) and b) had the money to pay tuition. In exceptional cases, someone in charge might have to be "persuaded" (read "bribed") to allow a very young student in, but the homogeneity of age that we see today did not exist.
