My ISP plan is 15 mb/s down with 2 mb/s up. I am currently connected via Wii LAN Adapter, but I've noticed the internet on the Wii U runs VERY slow - IE: any video played on YouTube (via app or browser) keeps getting interrupted every 4 seconds.
In the next few days, I'm going to upgrade to 30 mb/s down with 5 mb/s up...but that doesn't really affect the "relative" connection speed questions I have...
1) Is anyone else seeing huge discrepancies when using the LAN vs WiFi?
2) Why the hell is the U so slow with it's connectivity in general? This can't be helpful to BO2 connectivity, can it?
3) Is the LAN Adapter not USB 2.0?
Here are some tests of:  Wii U LAN,  Wii U WiFi, and  my laptop. During WiFi, router is 2 feet from Wii U and 30 feet from laptop.
 Wii U LAN download: 1.26 mbps
 Wii U LAN upload: wouldn't work
 Wii U WiFi download: 1.6 mbps
 Wii U WiFi upload: wouldn't work
 Laptop WiFi download: 16.22 mbps
 Laptop WiFi upload: 2.34 mb/s
Site: http://testmy.net (this one is the most telling as it can test all consoles)
 Wii U LAN download: 1.9 mbps
 Wii U LAN upload: 767 kbps
 Wii U WiFi download: 6 mbps
 Wii U WiFi upload: 874 kbps
 Laptop WiFi download: 14.6 mbps
 Laptop WiFi upload: 2.4 mbps
Site: http://pingtest.net (testing laptop WiFi only since U doesn't support Flash)
 Ping: 48 (500 miles away), 105 (2,000 miles away)
 Jitter: 6 (500 miles away), 3 (2,000 miles away)
 Packet Loss: 0 (500 miles away), 0 (2,000 miles away)
Site: http://speedtest.net (testing laptop WiFi only since U doesn't support Flash)
 Ping: 44
 Download: 14.5 mbps
 Upload: 2.10 mbps
In-Game Bandwidth (options>system info):
 Wii U LAN: 2.1 mbps
 Wii U WiFi: 2.0 mbps
So...essentially my laptop that is 30 feet from my router works 7 times FASTER than my Wii U that is plugged into the router (LAN)...and even more crazy is that my Wii U LAN is 3 times SLOWER than my Wii U WiFi?
########## UPDATE ###########
I upgraded my internet to double it was before, so am now at 30 mbps up and 5 mbps down.
NEW Speed Test (http://testmy.net):
 Wii U LAN download: 1.2 mbps
 Wii U LAN upload: 455 kbps
 Wii U WiFi download: 5.6 mbps
 Wii U WiFi upload: 810 kbps
 Laptop WiFi download: 29 mbps
 Laptop WiFi upload: 5.3 mbps
NEW In-Game Bandwidth (options>system info):
 Wii U LAN: 2.3 mbps
 Wii U WiFi: 2.7 mbps
So I talked to Nintendo Tech Support:
* "we don't have any information on how to speed it up, nor do we have information as to if there are limits on the internet speed of the U or the max speed the U can handle. The e-Shop has been down/under-going maintenance so that may be increasing lag."
And then I talked to Nintendo Consumer Support (because Tech said they'd have more info):
* "there's no information I have to help you - did you contact your ISP?"
And then I talked to "Advanced WiFi Support":
* changed wireless channel from "Auto" to "1" = no change in speed
* changed channel to "6" = no change
* changed channel to "11" = increased Wii U WiFi speed from 5.6 mbps to 6.1 mbps
* no other channels made a difference
* I have a Belkin router and there is a QoS (quality of service) setting that was on. Was told to turn it off, but made no change in speed
NEW NEW In-Game Bandwidth (options>system info):
 Wii U LAN: 2.3 mbps
 Wii U WiFi: 3.0 mbps (highest I've ever gotten). Last night 3/25 I actually had 4.8 mbps in-game all night and still had HUGE lag issues. Could be someone in my party or lobby with a bad connection that caused that though.
Additional Info From Nintendo:
* DMZ has nothing to do with speed - only has to do with firewall (same with port-forwarding)
* Wii U can handle up to 130 mbps WiFi
* LAN adapter "should" work well as it is 10/100
* Any game online (like BO2 multiplayer) should work very well if you have above a 6 mbps connection with the Wii U
* If your router was between $40 and $80 (mine was $40) - it might not be advanced enough to handle online gaming through the Wii U
* Was told to look into a better router
* Was told to contact my router (Belkin) and ask them for specific setup for Wii U
Will update this if anything changes for the better. Might just get a new router. All of this can't be helping the connection issues I have with this game.