I've never had problems with the MoXF6 keybed, although I'm a pianist I've been able to adapt well to it and to play piano tunes with a lot of expression. It is very lightweight, but it doesn't have a short up/down scope so I could reach dynamic levels from mp to ff without problems.
Its personal prefference... at my skill level my performance is like day and night, when playing lighter keys, i struggle a lot with the consistency of the dynamics... it all works much better for me with some heavier keys..
Like i said, all personal prefference...