I bought one ten dollar one to test it around a week ago. Cent OS x86/x32. Although I may not respond due to inactivity, feel free to PM me if you decide to set up the Linux Server.
Linux > Windows in terms of speed and memory usage. Linux is also cheaper.
Because Windows costs money to use, when you buy a VPS with Windows you are more buying the Operating System than you are the VPS itself. Linux, being cheaper, therefore is the better product in regards to the money aspect.
Windows also loves to take up your memory, as someone mentioned, so you can run more bots on a Linux Server.
I think your brother had said that about Linux because he was not used to it when he did try it. It's a huge switch going from Windows to Linux. Linux is more command/terminal based with less User Interface for everyone. Windows is more user friendly. It's easy to pick up the commands needed to start up your bots, though. Basic ones are used.
At the moment, after I saw the one 10 dollar one worked, I bought a second 10 dollar one. One is running a AutoWoodcutter + AutoSoulWars; and the other one is running an AutoMiner in the Rock Caverns and an AutoWoodcutter. According to the terminal, it is running at around 70-90% CPU. I might be able to run one more bot on each, but it would be pushing it.
I bought mine from burstnet.
Anyways, contact me if help is needed, and hoped I help.