Default Slow Wifi speed on Nexus 5.

I am on stock ROM. With Franko Kernel 32

My router is Belkin N150
My Laptop is a W520 purchased over a year ago i7.
My laptop is able to connect at 150 Mb/sec
My Samsung S2 is able to connect at 150 MB/Sec.
My Nexus will only connect at 75 Mb/Sec.

The samsung with a stock rom and stock Kernel is able to pump data over wifi much much faster than my Nexus.
I get 600 Kb/Sec moving data from my laptop to the phone and phone to the laptop
On the nexus I am lucky to get 300 Kb/Sec.

I have tried all the TCP/IP options in Franko Kernel. Westwood / Bic etc.

Whats going on here.
Any tip much apprcated.
BTW I am using channel 7 cause it has the least traffic in my area.