Each brand has their strengths. Zero has traditionally excelled as a commuter that people ride to work, ride home, and plug in overnight to recharge. With the SR/F platform they're taking everything they've learned from the last decade and poured it into a refined sport bike that you can go for a ride, take a leisurely lunch while charging, and then go for another ride. The bikes are quiet, smooth, and all sorts of fun. Special mention to the FXS as one of the most entertaining urban commuter/toys made in recent memory. EVERYONE should test ride an FXS at some point.
Energicas were born as track bikes. The EGO is truly the flagship as a flashy beast that will go fast, charge fast, and never overheat. But then the Italians started to realize a lot of us wanted comfier, more upright riding which led to the SS9. It goes fast, it charges fast, and it never overheats. It's also exceptionally comfortable. Yes, the bike shines most when you have a solid DC Fast Charge network around you. Which I do. Ultimately this is why I sold my Zeroes for an SS9. There are things I miss about my Zeroes but I am happy with my decision overall.
The LiveWire is surprisingly well-made. It's geared lower than both the other bikes so they made it exceptionally peppy from 0-114 mph. They also made some interesting decisions about cooling the components, including some clever battery cooling. It, too, can ride hard all day and not overheat. The decision to omit level 2 charging and the ergonomic position of the bike will frustrate some people, as will the $30,000 price tag. But it's a very, very good bike.
It comes down to personal preference, your riding style, and what sort of infrastructure you have around you. I don't think there's a bad choice in the lineup.