I think the problem is the classes need to be clearly explained in terms of what they do.
Wizards
Know lots of spells and can learn every arcane spell if they want or make new ones.
Have to prepare them in advance.
Can only cast a handful of spells at a time.
Make scrolls, wands and other magic items to make up for limits.
Sorcerors
Know very few spells.
Don't need to prep.
Can cast a lot of spells at a time (at least 50% more if not twice Wizards)
Use Metamagic to cover for the limits on their casting.
Can't use rituals
Can't make magic items
Are better at using magic items then Wizards.