The MakerBot Replicator+ is Faster, Easier, Quieter 3D Printing and a 22% Bigger Build Volume than previous model It has a flexible build plate for easier part removal. Redesigned Z axis movement and now comes factory leveled.
Honest review: The new software allows CAD-To-Print and multi machine management which is a real plus for schools and print labs. It is quieter, but not as big a leap to silence Makerbot may want you to believe. The build size is dramatic and the auto levelling seems perfect so far. The flex bed is great, but we recommend adding Buildtak for extra grip. All in all a professional machine easy to use.

The Makerbot Smart Extruder +, released in 2016 is the new edition of the Smart Extruder for 5th Generation Makerbots. It is a all in one extrusion system that attaches with magnets. This model is explicitly for the Z18.

A completely revamped experience for the 5th Generation and + Series of MakerBot 3D Printers. You can quickly swap between the reliability of the Smart Extruder+ or Tough PLA Extruder, and a new sandbox platform with the Experimental Extruder. Explore new materials, print faster with draft nozzles, and enjoy the same advanced jam detection, z-homing, and filament detection sensors as you have with the Smart Extruder+

The Makerbot Smart Extruder +, released in 2016 is the new edition of the Smart Extruder for 5th Generation Makerbots. It is a all in one extrusion system that attaches with magnets. This model is not compatible with the Z18.