The maps quickly go out of date as you can imagine always assuming that it was up to date when you bought it. Connection to the satellite can be frustratingly slow but once connected it’s not too bad. That said, it gets me around albeit that it sometimes wants to divert me off a perfectly good express road to take a longer route on the old road.
I can’t say I can recommend a make because the manufacturer went bust on my Chinese GPS so now I use a foreign one and rely on indifferent Chinese maps that seem to be permenantly out of date.
What are your requirements? I would have thought between Apple, google, and baidu maps on the iPhone, you’d have everything you need.
I thought Baidu and Google even has turn-by-turn functionality in China on iPhone? (they do on android so I guess on iOS too)
I found that as you go deeper into the countryside these maps services can have different levels of detail depending on where you are and what you need. so between the 3 they are a accurate as you can possibly buy. Apple (allegedly) has great/the best maps for smaller towns in China outside of the big cities.
the things that sometimes catch me out are:
-ending up somewhere without network to access the map data. you will likely only get this on china Unicom (and less so everyday) unless you go far west into far Tibetan areas. You can mitigate this by downloading/caching maps of the area you’ll go before you leave.
-running out of battery; get one of those portable battery pack things.
I also explore quite allot out of Chengdu using my phone. if you’ve got any other questions please ask.
I would get a portable battery pack and use your iPhone. Up to date, easy to use, doesn’t require buying additional hardware. There are tons of mapping options available on iOS, I would just Google for GPS reviews and see which one is best.