Upgrading from the stock cooler isn't entirely necessary, but it's usually a good idea. At temps ranging just a little higher than what you are at right now, the system can become unstable at times (do you experience lockups?)
You could get a better heatsink, i'd recommend the thermalright line (sk7 and up) or vantec aeroflow or similar.
Probably an easier (and cheaper ) solution would be to re-vamp your case cooling.. Cutting out your fans' pre-stamped grills from the case (with dremel or holesaw or similar) usually dramatically increases airflow (and lowers noise too) which results in better cooling.
Also, be sure that the heatsink is mounted correctly, as this is often the problem of high temperatures. If you'd like to see just a minor improvement of temps on the cheap, clean off the included thermalpad or grease (rubbing alcohol works well) and use something like AS3 or shin-etsu g751 or similar..


If you arent experiencing instability and you don't care to overclock or have high temps, i suppose it's not entirely necessary to do anything.. The stock cooler does it's job, it just doesn't do it as well as the aftermarket..

Hope this helps ya, cya round