Not sure if Dylan has been to China before. I went for the first time last year and saw Beijing/Shanghai/Guangzhou/Shenzhen. The only one with legitimately cool tourist stuff was Beijing. It was awesome to walk on the great wall of China, to see Tiananmen and the Mao portrait, the Temple of Heaven etc. That sort of stuff was really memorable for me. Shanghai was nicer in general but not really much memorable tourist stuff. Just nice shops, offices and bars...which quite frankly I saw plenty of in Hong Kong already. Shenzhen was terrible I only went there to get a custom halloween costume for like 8 bucks. Guangzhou I saw the tower and walked around for a long time and saw a soccer game. It was a good day but 24 hours was enough for me.
I just kind of hate china though because it's somehow a shithole yet not as cheap as it should be, the people are rude as shit unlike basically every other asian country, and they visa rape you with the fees and not giving you multiple entry unless you already have used up a dual entry. The one redeeming thing for me was seeing the sights in Beijing