to sum it up, Wizards are underperforming Sorcs
if you want to multiclass an arcane caster go wizard, if you want pure go sorc. of course on the easier option, but if you multiclass with the sorc it will be a lot harder to start off but end up a lot more powerfull
I think most people who have even considered that a wizard is on par with a sorc either dont understand how to play an arcane caster (its all about shooting fireballs...innit), or have never played a sorc and are just speculating.
but there is no right or wrong answer to this, its all a matter of opinion.