While I did not run the simulation provided by Bob I did run a few magi up to fairly advanced ages using the default 30 xp per year and reflection. Of note to this conversation are these two, the ones that went the longest (150 years each).
Adelbert of Gurnicus
Ranulf of Flambeau
Adelbert is 180 apparent age 101
Ranulf is 174 apparent age 55
Difference in actual age 6 years, difference in apparent age 46 years. One of them used longevity rituals that were strong for his age, the other used longevity rituals that just barely let him skate by without loosing characteristics.