This is still an issue three years later. Nexus Mods are still slower than molasses to download anything. Seriously, on Chrome it's so slow that it keeps timing out or a question mark appears on my download page. Then it says 6 hours, to download a 60 MB file? Really 6 hours. It's a joke. Also, I found that disabling adblocker doesn't work. It's still really slow. It seems the only way to speed them up is to cough up and pay them. Although judging by how badly they treat the free users, I'm reluctant to pay them anything.
First of all, this isn't a NMM issue but a problem with the Nexus servers. If your 'issue' with download speeds persists, post about it in the correct forum and admins will tell you about the how and why, instead of digging-up an old thread that isn't directly connected to what you're going through, because, this is not "still an issue" as if downloads have been slow over the past three years. It's just your 'luck' that you try a download in a moment the servers are overloaded. Bummer, eh.