Differences are many, but I consider all the reasoning behind it unfounded. The dispute between Shia and Sunni comes many years after Mohammad's death, and that within itself should be a clue that shows that it is fitna. And people that say that the differences between them are items of Aqeeda have forgetten that the differences do not come out of the Quraan, as we all share the same exact book. The differences come only from those that spoke and ruled after the death of Mohammad (SAAW), and for what? For political gains and domination; disputes over the rule of the Islamic empire. Two hundred years after the death of Mohammad (SAAW), the "Saheeeh" books are written claiming this and that and claiming it to be the sayings of Mohammad the Prophet... and they follow it with "Isnaad" which was their 'filtering' process of figuring out which Hadeeth is correct and which Hadeeth was a lie... and yet all 4 of those major Hadeeth books on the Sunni side forgot ONE important filter, which is: if the saying contradicts the QURAAN or not... and this is probably true for the Shiaa side also. Why listen to someone that says "I heard so-and-so say that so-and-so say that he heard the Prophet Mohammad SAAW say... " when you have ALLAH's words right in your hands TELLING YOU everything you need to know...