They work fine, you need to check that the stack is the correct height for clearance, usually leaving out the top friction plate. If the stack is too high, the outer plate can hang up on the lip of the clutch basket, preventing the plates from packing down. I have seen two clutches burn out because of this.(The original plates are full width at the edges, repro bonded plates are only the thickness of the metal here, so the top plate can sometimes just drop off the basket, usually just after you have enough confidence in the rebuild to do a nice long ride) Otherwise, the Kiwi/Greer/ repro clutches work fine.

It is worth pointing out here that original clutches are virtually bullet proof, unless very worn or the metal plates are warped, they will work just fine.They are a Chief clutch, so somewhat overengineered. You can leave as many as half the springs out to lighten the action and they still work on a scout. I have fitted new clutches to virtually every customers transmissions, and am more than happy to take their original plates off their hands for personal use. Cleaning them up carefully, it isn't unusual to  find Raybestos trade  marks still visible. ( Don't leave them in a degreasing tank, many solvents will turn them into soggy sludge.)

As for aluminum over steel as a base material for the bonded plates, I could not say. I have never noticed a difference, but a quick internet browse ( always a dangerous thing ) suggests that aluminum MAY wear quicker against a steel hub. Would be interested to hear others more informed thoughts on this.