This is ghetto, moped factory is really nice.
If you're on the cheaps, buy the stock.
If you want clean and nice, buy moped factory.
Maybe some day if sachs takes off I'll make some aluminum ones machined to fit all nice like - but I don't see that any time soon and graham has got the market corned on the "nice" end of the market. The MF ones look like you press the sleeve from your old bushings into the new ones.
Also, if you buy moped factory - you're buying a Graham Motzing's creation, which is cool and awesome.
I think MF bushings are maybe PTFE... They might be some sort of polyurethane too. Not sure. They come from Graham though so I'm sure they're really nice and way better than the flimsy rubber ones that come stock. (edited)