I think there may also be a certain amount of balance issue between Summoners who do not suffer from the lack of spells and Enchanters and Sorcerers who suffer from the lack of spells for aspected magicians at all priorities.
Yes because when you give free spells to the aspected it feels like the summoner suffer and viceverse.
What i did with the summoner was that make the Summoner aspected can summon any kind of spirit but only bind those from his tradition.
I house rule it like this for aspected Magician:
Priority B:Magic 5, one rating 4 magical skill group, 4 spells/preparation/whatever.
Priority C:Magic 3, one rating 2 magical skill group, 2 spells/preparation/whatever.
Priority D:Magic 2, 1 spells/preparation/whatever.
Personally i dont think the Mystic Adept need to nerferd now that it cost 5 karma per power point. But i never had one of those in my table on 5th