I've purchased it to have a 88 weighted keys keyboard, with good sound (I'm a Roland FA-06 owner and I love Roland Sounds), and the lighter possible.
With 15 Kg, is the lightest option possible, with all the power from Roland. The key action is not the best on the World, but I find it really comfortable.
It's true that it have less memory than the Fantom Ex, but I've installed 4 sound extensions (plus the 3 Supernatural) and it's all I need for stage performance. That's the key: It's a good keyboard designed mainly for stage (imho)
The body is plastic made, but it seems quite robust. The manual misses some points (Aux In activation, i.e.), but there's a lot of information on the net.
Great quality / price ratio: Very happy with my purchase.