Am facing similar issue with my Wireless internet connection.
Ubuntu 14.04 as a guest OS on Windows 8.1 using VMware workstation 11.0
I get around 1000 kpbs(it's enough for me...) on Windows 8 while its "snailing" on virtual machine. Here's the output of that script.
I would love to see 1000 kpbs on my Ubuntu as well. It's hurting me a lot.