I went with the Stewart pump for the obvious benefits. Otherwise i would have gotten OEM bmw. The plastic impeller is no longer an issue and the bearings are likely to be better quality than the aftermarket options. Also it guarantees that you will have proper flow vs. other pumps that have had flow problems at idle like jbeurotech said.
Edit: The additional $30 shouldn't be that much of a concern when its a part to keep your engine from overheating. I'd rather spend a little extra to protect myself from larger repair costs and the headaches associated with them
Last edited by be-doubleyou; 09-30-2011 at 04:47 PM.