It really depends on what you plan on doing with your computer. If its a CPU intensive task for transcoding or graphics rendering, or games it could give you a boost. For everyday tasks, there won't be a big difference.
My advice would be to Do a light OC like 3.2GHz, and see if you notice a difference in speed. For that, you should be able to keep it at stock voltages, or a small increase, maybe to around 1.3 or 1.35V. I'll let someone else help you with the voltages, because I don't have experience with that chip. But just keep the voltages as low as you can without the system crashing when you boot or run an intensive task.