Like I said though, my speeds are very consistent once you stick the proxy server in the middle, which I already needed anyway to get good speeds on the PS Vita.
People who are claiming "it works fine" or "it IS faster on Ethernet" I can guarantee have slow broadband and/or WiFi problems to begin with. We already have several reports of the Wii U not exactly having the best WiFi reception for some people, but in my case I can tell from the router stats its achieving the maximum speed the Wii U is allowing.
As I said above, the proxy server takes the broadband connection completely out of the loop so I can prove without question the maximum speeds the Wii U can currently achieve and they are WELL below what you would expect for a console that has 25GB downloads on the eShop.
Interestingly the 3DS actually runs slower when using the proxy server, only managing 200K/s when if left working directly it averages around 800K/s. That makes the Wii U situation even more embarrassing as the 3DS its only 802.11g compared to the Wii U at 802.11n, yet is able to achieve pretty much the same speed as the Wii U under the same configuration. (no proxy)
[WII U UPDATE 3.0]
Dramatic improvement in performance!
I was able to get an average of 2.5MB/s from the USB adapter downloading to a HDD with the proxy enabled. Without the proxy it fluctuates wildly but still seems much faster than before, I suspect it may average around the same but its harder to measure when it fluctuates so much. Either way its a big improvement.
Downloading to internal memory still is garbage at an average of about 400KB/s, it did peak a few times at 1MB/s but then seemed to stall for a second or two (while it saved the data to the storage no doubt). As previously suspected it seems the internal storage has very slow write speeds which is bottle-necking the download. Its annoying as if I had known the built-in memory would be this bad I might not have bought the Wii U Deluxe. This is particularly relevant as saving to a cheap USB memory stick performs almost as good as an external HDD, doing between 1-2MB/s even while playing LEGO City Undercover at the same time which is excellent compared to PS3/Xbox 360 which slow down to 500KB/s when background downloading.
One of the big problems with the Wii U is that the downloads seem to be split into many different smaller files which slows down things a lot as the nature of TCP/IP is you start off slow with each connection and gradually speed up as it detects you are capable of handling it. So its far better to download one big file rather than several smaller ones.
The new background installing seems to be a huge problem too now as when its stalling the Wii U becomes unresponsive when trying to move between sections of the UI. I just tried to view Download Management and its just sat there on the loading screen for about a minute. The same thing happened when I tried to go into settings earlier, I had to wait several minutes for any response at all, the home menu just locked up.
There is one good thing though, background downloading/installing doesn't seem to affect actual retail disc playback at all. Clearly the issue is downloading to the internal storage while also trying to read the OS from internal storage, is a bad idea. I While in a disc based game you aren't really doing anything with internal storage (except when saving the game) so things work smoothly.
Edited by Alex Atkin UK, 27 April 2013 - 03:38 PM.