I have..but I haven't run a campaign since I made the changeover, my group broke up when half of it moved to NY. As for why..Well it fits the concept better, and IMC, I removed the 'memorize a roster' aspect of wizard spellcasting anyway. In my campaigns everyone's essentially a spontaneous caster, though Wizards have more flexibility in their spell list and sorcers have more freedom, since they only need an component/ focus item if its essential to the spell effect <eg a gem for Magic Jar and Trap the Soul> for instance, asode from EXP and sacrifice requirements. I'm tinkering with the idea of going Kismet's route and making 'Sorcerer' a template that grants 'virtual levels' as you level in other classses, representing your delving into your 'innate, instinctive gifts' But all this is my 2 cents, your mileage may vary, as ever.