You won't get the ability to use dual channel. The CPU has to be physically connected to the pins of the memory, so the read and write times will take longer, because the CPU won't have 2 places to right simultaneously. Each read/write to the stick the CPU wants to do will have to wait to the previous one is done.
Now, in NORMAL internet browsing, you probably won't see much loss of performance. But then again, with normal internet browsing, you don't need 8 GB of memory.
I would say, do dual 4GB sticks if its possible, but if you have a single stick of 8, then that's what you got. Unless you are doing memory intensive tasks like video editing, I don't know if you will see a difference. Like, if you don't know what you're missing, then who cares.
Dry