I believe the pulleys in the SLX are bushed not running on bearings so won’t be quite so lovely but apart from a couple of gel wrapper’s worth of weight, cosmetics and price that’s about it I think. Perfectly functional, bit less bling.
My WR Zee mech got a cage transplant after an unfortunate incident and on closer inspection it turned out the bottom pulley had dug in chain marks running across it (yep I was that idjit with a short chain) so ended up with replacement roller pulleys too… It’s not really a Zee anymore, but it’s a cool mech. Thanks, Mat!