MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
i have some bearings with metal seals similar to those shown at the amazon link you posted. in my experience, the bearings with metal seals have the highest resistance. my guess is that they are made for more of an industrial application and thus are assembled with a heavier grease. but, that is just a guess as I am not a bearing expert.
All of the PTFE exit positions work equally well in my experience.