I have no problem driving them with the DZ-2001L, it's the latest version. I figured out the CSM2 boxes, they need to have aux power or they don't work. Odd that the documentation appears to suggest the block control is optional, so I figured I didn't need relay power.
Other than the CSM2, I know of no "new" Lionel driver for the DZ-2500 switch machines.
Gary, the SER2 IS the box that won't drive the DZ-2500C switch machines. They totally ignore it's output. I can see it on my 'scope, and it looks fine, but they don't work. Connect them to the DZ-2001L and they work.