As mentioned, ZJK and Viscaria are pretty similar in design, and should play pretty similarly to each other. The Viscaria's handle is marginally bigger, which affects the balance and comfort a little bit. Handle is important though as it's more than just about comfort - it can very much affect your ability to keep a particular grip during a rally when you are moving around.
Harimoto ALC is half way between a Viscaria and W968, but obviously its construction is more like a W968 than Viscaria/ZJK. It is very powerful on full strokes, with very good touch because of the deadness of ALC, but no real spring to give your half-hearted shots any real kick.
Stiffness: ZJK/Viscaria > Harimoto > W968
Hardness: ZJK/Viscaria > Harimoto = W968
Dwell: W968 > Harimoto >> ZJK/Viscaria
Bounciness / Speed (over table): ZJK/Viscaria > W968 > Harimoto
Speed (mid table): ZJK/Viscaria > Harimoto > W968
Speed (far table): W968 > Viscaria/ZJK > Harimoto
If you play a game based on touch and powerful attack, W968 and Harimoto are probably better. the Harimoto is much better in this regard for amateurs, who probably don't benefit from the additional gears of the W968.
The ZJK/Viscaria is a very good blade for blocking and counterlook games based on speed, especially when you are borrowing speed from the opponent.
I have a Harimoto ALC for sale at the moment, PM if interested.