The best motion units are ones that have mechanisms made by UltraMek or Leggett and Platt. Look for their labels by the footrest when the chair is opened up. I will ONLY carry manufacturers that use those to brands of mechs. UltraMek is made in Tennessee, Leggett will be either Mississippi or China for production, though I find due to the high cost of shipping now from China, all mine come with the "made in USA" sticker on the mechs. They are equal in quality.

Power mechanisms take less wear and tear than manual units. Manual units get slammed around and abused more, so they can shear rivets, if you want a long last mech, get a motorized one and use a surge protector on the plug, they are problem free.