So After some playing around I got all my answers.
To clear this up. Most routers have a stander 4-5 inch antenna for wireless G ( 2 -3 of them for wireless N) there screw on and off quite simply.
and ones like it are simply a bigger antenna. Depending on the setup it may help a little , or alot
For me. When I put this on my friends router. (access point) It did very little...
signal went from 15% to like 20%
However when I replaced the antenna on the wireless PCI card It went to about 50% and after I moved it around, (came with some cable before the base) I was able to get 80%
So depending on the setup this is what these things can do.