I had posted a temporary fix that I found has worked for a number of users on one of the other threads but it got buried.
Change the DNS settings on your Mac or iPhone/iPad to: 220.127.116.11 & 18.104.22.168. I tried on the Actiontec but it failed since my devices kept pulling Telus' DNS servers. The DNS has to be changed on the individual devices.
After I changed the DNS to the above addresses on my Mac and my iPhone, I saw a significant speed increase and ended up at the full speed my 25mbps could handle when downloading OSX El Capitan as well as iPhone apps.
To change the DNS on your iPhone:
Try downloading an app to see if it worked.
On Mac OSX:
You should be good to go at that point.
I was finally able to speak to a manager a Telus about this. They confirmed the issue is that Telus needs to upgrade their links to Apple but they are not doing that any time soon. Though it is on a upgrade "list". So until Telus decides to spend the money to upgrade their links, Telus customers will experience slow connection speeds to Apple whenever Apple released new software as their ports to Apple get saturated. When I asked the manager why there has not been an official Telus response in the forums here, they said until they do upgrade their links, which there is no timeframe on, they will not post an official response here. Poor customer service.
It has nothing to do with Telus upgrading anything. It's an international issue on Apple's end affecting many ISPs where Apple's content distribution network is overloaded and that has been confirmed. The "Manager" at Telus you talked to won't have any access to any pertinent information on this and sounds like they gave you some placating explanation instead of confirming the correct source of the problem.
From my own testing only Telus internet is affected. I know how it works, you don't get to speak to a real manager when you ask to speak with one. I had to work my way up to speaking with a manager, who did sound well informed about the situation. Now would be a great time for someone from Telus to chime in and clear things up if I was infact misinformed.
Dru from TELUS here.
Thank you all for bringing this to our attention!
Your input was invaluable in helping us identify a challenge at a connection point between our networks. We are working closely with Apple to increase peering capacity and everything should be resolved soon.
On behalf of the TELUS Neighbourhood team, thank you so much for your patience on this matter and sorry about the inconvenience.