I don't hate the plastic. Yes, it feels cheap, but in my experience it holds up well. Downside of the low weight is that keyboards don't sit as solidly on the stand. YMMV, but the it's not that uncommon for me to inadvertently push the Krome off balance when playing. Occasionally happens with the MODX8, too.
The cheap feel is more in the action. An all plastic enclosure with an excellent action would probably feel a lot better.
I've had the Fantom-07 here for two days now, and am not thrilled by the feel of the keys. It's just okay, nothing more.