Well using recycled oil is totally illegal here, but it doesn't stop many people from using it to save money. Beijing is fine, but the pollution is awful and a lot of times it seems like the city has a facade pretending to be a nice place, when really, as Obi Wan would say, "a wretched hive of scum and villainy." That being said, if you have to be here for business there's a lot of money to be made, but most foreigners I know are just counting down the days until we can leave. Shanghai is better, and Hong Kong isn't even really China (at least not culturally which is nice). It is a fine place to visit though if you were thinking of coming.