My VML arrived today, just in time to charge it up and shoot a baseball team + individual shots out at the ole' ballpark this afternoon.
I gotta say the portability factor of this thing is sweet! Clamp it to the light stand, plug it in and you can carry the whole works with one hand! Prior comments in this thread notwithstanding, I don't see any problems with the build quality either. It seems constructed well enough to get the job done. I did read the complaints/warnings about the wimpy clamp on the VML and secured the connection with a bungee strap. No worries.
This is the first time I have used one of my Alienbees outdoors, and the lack of an audible recycle indicator is a pain. You can't even see the ready light in the sun. I guess it's time to start lobbying for a couple Einsteins. 
Anyway, the bottom line for me is it's a great one-light power source. That's all it can really do, though. The recycle time gets impractically long when you go beyond 640ws. If you want to use more than one monolight out in the sun, I definitely recommend a separate VML for each light.
Once home, I did a little measurebating, using the following high-tech equipment:
1) A consumer-grade digital multimeter, plugged into the spare outlet on the VML to measure voltage
2) A consumer-grade clamp-on amp meter, stuck through a split power cord to measure current
3) A consumer-grade digital wristwatch to measure recycle time
No-load voltage on the VML was right at 121 volts. Take this data with a grain of salt. It may be statistically significant, but I wouldn't call it precise.
