I tried disabling WMM from QoS in my router. I then reconnected the IPAD to the network and still had the LOOOONG download times on videos. I was trying to download a single episode of Big Bang Theory from ITunes and it told me it would take over 600 minutes.
What I finally did that appears to have resolved the issue was completely disable all security on my Wifi network. I then connected and tested. Speeds were fine using speedtest app, and download times were down to about 20 minutes or less. Apps were installing quickly and internet speeds were much better.
Once I had tested all that and it looked like the problem was resolved I went back into my router and did the follow to make it more secure. Heres what you do, the steps are different on all Wifi routers but the settings should all be there, you might have to poke around a little.
First TURN OFF SSID broadcast (Write it down so you have a record of it, with CaSe SenSitiVitY in mind). Once you do this you will no longer see your wifi network show up in the list of available networks. You must manually enter the SSID into any devices that you want to connect to the network. You may have to do this immediately as the SSID will turn off and you may lose connection. Get reconnected by manually entering the SSID (CASE SENSITIVE) and reconnecting.
Now go into wireless settings and look for MAC Address Filter
Turn it to enabled/on
and Tell it to "ALLOW THE PC's BELOW" NOT the other one to BLOCK the PCS BELOW
Find the WIFI MAC Address for your wireless devices. For the IPAD you can find it under settings>general>about and its at the bottom of the table called Wi-Fi Address. Enter that set of numbers WITH COLONS usually. The MAC filter should give you examples of how to enter the MAC, with or without Colons.
For PCs you should bring up command prompt and enter ipconfig /all and locate the wireless connection and look for the hardware address. enter the hardware address as the MAC address. I believe Windows displays hardware ID's with - instead of colons so just substitute colons for dashes.
Google other devices you may have to find out how to get their MAC address.
Once all of your devices are added to the MAC filter you will have to manually add each device back to the network. My recomendation is to test with JUST the IPAD first make sure the speeds are fine and then add the rest. If this procedure doesn't fix the IPAD speeds then set the network back to the way it was before with security.