Wa'alaykum as-salaam wa rahmatullah,
Have I benefited from brothers who are Shias? Absolutely! I know a few and they are great Muslims, mashaAllah. As for benefiting from Shia-ism, I must say no. My opinion does not come from videos and articles. With new endeavors and added responsibilities, I have not been able to keep up but I used to be a regular member at one of the Shia mosques in our area. Furthermore, I alternate between three Shia mosques every Muharram, driving as much as 45 minutes one way to attend lectures and processions although I am always on the sidelines when it is time for chest-beating.
What I have noticed is that if I learn one good thing (from these meetings), there are another five things said that leave a bad taste in my mouth. For example, this past Muharram, the mosque I went to was broadcasting a live video feed from another Shia mosque in another state. The mosque I went to was low on budget and apparently these "scholars" charge a lot for Muharram lectures (something shameful if we consider how hufadh lead Taraweeh for 30 consecutive nights, standing hours at length, free of charge...sometimes they are given a humble token of appreciation at the end of the month). Back to the Shia mosque! So I was there and this "scholar" who had the same accent and style of delivery (same hand gestures, same tone of voice, same public speaking mannerism) as Ammar Nakshawani wanted to highlight the merits of one of the wives of the Prophet [saw]. "Well this is a first", I said to myself. The "scholar" began talking about Umm Salamah [ra]. He spent half of the time, if not more, bashing Ayesha [ra] and Hafsa [ra]. Things he said, I could have refuted more than half of it off the top of my head, without any need for references or refutations. So it occurred to me....they have a tactic. They cannot have a lecture on the merits of one person without discrediting another. And honestly, there is no benefit to attending such a lecture. You walk out knowing about the merits of Umm Salamah [ra] but your spirit is disturbed because another two Mothers of Believers [ra] were insulted.
You may ask why do I subject myself to such experiences? So that I am convinced that Shiaism is not true Islam. And I am!