Ertai will probably disagree with me on this
but I think that sorcerers give you less flexibility than mages, because they have a smaller pool of spells to ultimately choose from, so they usually end up casting a smaller number of different types of spells more often. Sorcerers are your quintessential battle mages, because a high level sorcerer can cast a spell like chain lightning 5+ times in a row and not many opponenents will be standing after that. But the spells that you might not use often but are important (divination, greater malison, lower resistance) you might not want to waste spell slots on them.
It's not a question of what is better, it's a question of how you like to play.
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Memnoch - Custodian of the Order of the Holy Flame 