Priced the same as Yamaha KX8, the new version (gray metal) of Fatar/Studiologic VMK 188 Plus seems to provide (from most reviews) a more evolved action (Fatar TP40GH), while the KX8 only features a standard Graded Hammer (high end Yamaha digital pianos use the third generation, GH3). From a user review, the Yamaha KX8 touch is very lighter and its keys looking and texture aren’t as nice (fingers tend to slip from the black keys). The Studiologic VMK 188 Plus action is also said to be more pleasant than with the old SL880. The Fatar weights 20 kg vs 15 for the KX8 (the later is made of plastic only).
A video is available here. We can find the VMK 188 Plus at 479 euros. A problem has been reported on a unit (where white keys response wasn’t homogeneous), however the overall quality seems better than with previous models. A 76 notes version (VMK 176, 18 kg) is also available.
One of the most acclaimed master keyboard was the Roland A-80, that was released in 1989 and weighted 30 kg ! (was priced more than 1500$). We can watch a video here, featuring a nice song that uses piano samples from Reason.