It's a (series of) range requests, so, it's (somewhat) different each time.
Given that the master is located in the US (+ CloudFlare), and the mirrors in Canada (-na), Western (-fr) & Central (-pl) Europe, I'd indeed expect slow to downright terrible results in Asia, doubly so in China, because, err, The Wall.
I'd try the -na and -pl mirrors, just in case, but I wouldn't necessarily hold my breath

.
With sane peerings, the limiting factor is usually the device's I/O, and/or the Wi-Fi signal itself, on devices with not-downright-terrible I/O.
As a random example, I'm seeing roughly the same 1.4MB/s that I see with LAN<->LAN Wi-Fi transfers to the same device in the same location on the same network:
Code:
#################--- 88.1%
#################--- 88.1% 155.6 kBps 26:52 ETA
#################--- 88.1% 495.2 kBps 8:55 ETA
##################-- 90.3% 1006.9 kBps 0:13 ETA
###################- 95.2% 1207.8 kBps 0:02 ETA
###################- 98.2% 1449.5 kBps 0:00 ETA
###################- 99.2% 1495.2 kBps 0:00 ETA
###################- 99.3% 1547.1 kBps 0:00 ETA
#################### 100.0% 1444.0 kBps DONE