I tested all 3 devices. PC, iPad, and Android Phone. It's 2 in the morning with 1,800 players online, so my ms should be pretty low.
Here were the results
LATENCY
PC
70, 80, 90, 110, 90, 110, 80, 120
Pros: None
Cons: It affects sparring, other than that, the game runs pretty well, as long as you don't have weather effects on while it's snowing, and full screen with 100% zoom.
iPad
70, 68, 69, 61, 60, 60, 78, 70
Pros: iOS is really optimized, as far as settings go, it all depends on your device.
Cons: None
Android
70, 70, 70, 64, 69, 81, 72, 70
Pros: Android is also well optimized, Almost always at the same number in ms.
Cons: Probably none, except for some slowness here and there when you have weather on, and zoomed out a bit. Might just depend on your device.
SPECS
PC Specs
gtx 750 Ti
amd athlon x4 860k
8gb ddr3 ram
cat6 ethernet cable
windows 10
all drivers are up to date
Really doesn't matter which PC I use, my laptop gets the same latency ranges as my desktop.
iOS Specs
iPad Air 2
iOS 9.3
2gb ram
Android Specs
Samsung Galaxy s4 Active
Android 5.0.1
2gb ram
Summary
Even when plugged in, PC latency goes wild. Even when there are only 1,800 people online, PC latency goes wild. I remember when the gap between them was only 10-20ms, but now it even gets double the latency that mobile gets? That's pretty crazy.
When there are a lot of lag spikes, basically when there are 4k+ online (4,300), only PCs start getting disconnected. There will probably be a lot of re-dos in mixed gst, if this issue continues.
This mostly only affects sparring, and a smaller number of players (when compared to mobile), so I'm sure it's not the #1 priority, but since gst is coming up, I was wondering how/if this will be fixed. Maybe it's time to switch to something that can handle graal? I wouldn't mind downloading an iClassic Client.
Side Note
Loading the game takes super long sometimes on PC. I've tested iPad at the same time. iPad loads instantly, while PC sometimes takes minutes, due to having to reload when the green bar doesn't continue to load.