Ah, come on, J-10 isn't as capable as an F-16 Blk-15 now? Please!
It's not exactly state of the art alright, but let's at least give the Chinese the credit they deserve. J-10's a good 4th gen fighter that can do everything that a Blk-30 Viper can do, and then some. It may have Russian engines, but tell me what western aircraft manufacturer doesn't outsource components? Believe me, there are a lot more "made in China" items in Russia then there are "made in Russia" items in China. As said, China is pouring a lot of money and resources into this project and sooner or later, it'll start flying with a well-performing Chinese engine, bringing the total ratio of indigenous components in J-10 to over 90%.