I'm curious how much use old Z-corp machines are still getting these days??

I own a Z510 that hasn't had any use in a while. Its funny, however, because it seems like the powder-based systems are making a comeback what with the new HP line of machines.

I have not done much search, but I wonder if ZCorp machines can be reconfigured to making "green" parts for metal 3D printing - again, not too dissimilar to how the metal HP printers work.

Anyways, curious what others think about the ZCorp line. If its worth holding onto, if there are (or could be) any hacks to make it more relevant in today's market.