Yes I’ve done both but in 2018. I prefer Shanghai. Even Peter Pan is better there but culturally you’ll feel like you fit in more in Hong Kong. People there know how to queue and don’t let children use the restroom in public which can be shocking if you’re not prepared. Disney is very good at cleaning it up quickly but I wouldn’t step in puddles in line and in places where the queue isn’t enforced so well with very clear boundaries such as in the Snow White Castle, be prepared to be shoved out of the way in Shanghai. I just went with it and stood in the back. But the park is stunning and the rides incredible. Everything is so new and the people are incredibly kind and nice.
I did have to get the visa and yes it’s good for ten years. I did some kind of service so I didn’t have to drive to Houston. Just Google it. Yes that’s only for mainland China. At least until Hong Kong is fully pulled back in. I’m not sure when that will be. I think it was some kind of 20 year gradual thing.
When I went was before they redid the castle in Hong Kong and we got a club level room in the gorgeous Disneyland hotel so we could get the free fast passes that come with it. The vip tour was actually very cheap here as well compared to the states. It was a small park though, along the lines of Paris but only the one park. The most important ride to ride here is the monkey one. Their version of the haunted house. They don’t do ghosts in China so it’s a twist on that to avoid ghosts. It’s unique to this park and a fun trackless ride like Mickey and Minnie runaway railway style but even better. You don’t really need more than a day here imho.
Shanghai we did two days and they sold packages of fast passes so like all the thrill rides or all the family rides or a combo pack. They also sold individual passes so for example we bought two extra rides on Tron which was our fave ride in the park but you must also do pirates, go thru the castle cuz it’s the only Snow White one, ride Peter Pan too cuz it’s so modernized and gorgeous. The castle is incredible. Again we stayed in the Disneyland hotel here. You could prolly just do one day in this park with fastpasses but I enjoyed the more relaxed pace of two days.
I cannot help with construction since it’s been years but I booked everything all by myself. I found both these official Disney sites much easier to use than Tokyo Disney where I found they really cater to Japanese. Not so in China. It felt more like they wanted our business in China it was so easy to figure out.
But they same guy on YouTube in Japan does videos about Chinese Disney parks too. I actually booked my entire 21 day Chinese vacation myself. It was honestly not hard. I used day tour guides with packages I wanted that included the things we cared about like hiking the Great Wall. I just did a lot of googling and I buy frommers and other guidebooks but I honestly always start with looking at organized tour plans such as Adventures By Disney. Pick the things I like from those tours (and I honestly choose the same hotel me which you can book on your own for much cheaper and you know they are good if Disney uses them but I do compare to TripAdvisor too) and then add the things I find on my own that appeal like going out to the Panda Base two hours outside of Chengdu which was soooooo much better than the one in Chengdu that Disney includes on their trip cuz we did that one too.
Best trips I ever have are the ones I build myself like this because they are tailored to our interests. I used China Highlights for a lot of our day tours. They would pick us up, drive us around, take us to all our daily events like say a cooking class and hike up the birthplace of Doaism and inspiration for Kung Fu Panda, they spoke great English and I can vouch for them. They will take good care of you.
You cannot drive/rent a car in China unless you’re a citizen so you’ll have to hire drivers and/or use public transportation. In Shanghai I highly recommend the side car tour. It’s fun and they’ll take you to places off the tourist radar. Run by expats so you’ll hear it like it really is.
Any questions let me know for OP. I prolly can remember a lot of details since I did plan it all myself and it was one of the best trips I ever did. Honestly ruined Japan for me a bit.