Just wanted to give my 2 cents on the Iran vs GCC countries discussion a few pages back, in light of this recent announcement of Raisi's visit to China. I do think that overall Iran has a far greater potential as a Chinese partner than Saudi Arabia et al. They are much more industrialised with a more developed scientific, technological and manufacturing base. They have their own space and ballistic missile programme, and their military is more experienced and competent than the arab counterparts. Plus they have a comparable amount of oil and gas reserves.
But of course potential does not translate to real world benefits and I agree with a lot of other posters that Iran definitely has not been as open to Chinese engagement as now the GCC have shown with the China-arab summit end of last year. I think one of the issues is that with all the sanctions placed on Iran over the decades, their government has emphasised independence and non-reliance on any foreign entity as a top priority, so there is a real reluctance to allow foreign investment, even from China.
While a lot of this is on Iran itself, I do think China can also play a role in encouraging more cooperation and this visit is a very good sign. Overall I'm optimistic that the GCC pivot to China will actually decrease persian-arab tensions.