Slower Processer, slow Cache, worthless to a extent.
Put the few extra dollars in and use the suggested above.
We've been discussing the difference between OEM and Retail in another topic just there now.
OEM is just the processer - no heatsink, fan's, thermalpaste etc.
Retail - you get everything which you would do if you are going to buy it from a shop - heatsink etc.
But OEM is normally better because it saves you alot of money allowing you to buy another BETTER heatsink then the stock one you get with retail.