This is an odd one.
I get 12mb download speeds on my home wifi if i do a test from my laptop or girlfriends iphone. If I do the test on my Nexus i only get about 1.5mb.
If I reboot the router (Draytek) I get the full 12mb again for a few hours then it drops right back down to 1.5mb.
Now I know you are all thinking straight away its the router but I have recently changed this from a Linksy router to the draytek and had the same problem with that one, so it would appear it is my Nexus.
I am running PA with the latest Kernal for it.
Any ideas or help?