As an alternative to a real piano, at the moment there probably isn't one. As an alternative to a VPC1 then this will depend on your requirements, what music you play been the main one.
I play and study counterpoint, this can be in four parts, including suspensions, single, double or triple, it is these suspended notes that present the most problems on hammer simulated actions, as described in the Vidal keyboard, this seems to be addressed finely, although this is a new product and time will tell here. There is on the VPC1 for example, constant resistance to each key held, resulting in double triggering and fatigue over time, this is my experience with my technique.
For my playing, which is within the four middle octave range, I would probably benefit with a 49 key semi weighted, Axiom been one I liked in the past. But other than a real piano, I only see the Vidal as a proper alternative, again, this is based only on the early information given at this time on this product.
Nick