I sold my X500 to Hampton a few years back. That's a solid unit.Don't do it. I've got one sitting on the shelf. It's too noisey. If you want it, I have an X500 that's still in decent shape.
I will say for the $600 I spent, the Denon MC6000mk2 is a good total package and it's rack mountable. 4 stereo channels (each switchable) and 2 mics. Mine also came with the full version of Serato.