Ok, first delivery - pleasantly surprised by how accurate and up to date the tracking was, definitely not just a guy writing random things into the log. I had a notification on my phone next day after the log reported the package as delivered to the destination country, and the service (SunYou) was apparently able to find me in the database of a package delivery company I use when buying computer hardware in the local shops, and take advantage of their services (probably saving a couple of pennies in the process), that is quite impressive. And the item only took two weeks to get here.
The other item is taking longer (four weeks right now, still on the way), so the shipping time may vary, but that's to be expected (China post Registered AirMail).
Looks like you have 15 days to leave feedback after you confirm a delivery. It seems it's still possible to open a dispute even after that in case of problems, slightly odd, but ok I guess.