[Christ]

Frank -
The OEM tie rod's bearing surface is perceptibly much further from the point of strain, making leverage on the bearing surface. The rod ends (when done correctly) mount just about flush to the knuckle, with about 6mm clearance to allow flexing. It lessens the leverage that an impact has on the bearing surface. It can also often mean adjustability in the size of the bearing itself.

They're basically the same part, but the design of the tie-rod end puts the bearing's contact surface further from the fulcrum, is all. It's a minor difference that just allows for less deflection, especially after nominal wear has started.

I think the bumpsteer comment was a little outside the normal operational parameter of average people, though. It does, by my experience, make it easier to steer, though.