What is really cool about the AlienBees is that they consume very little energy making them great for battery work.They don't use transformers to elevate the current to store in the capacitors, but instead use multiplier circuits designed by Paul Buff.
I can shoot an 800 with 150watt inverter on a 15Amp batt for a couple hours heavy shooting. What is really cool about this outfit is that it is ultramobile. Suited for very fast work.
Yes, generators are great when you won't be jumping all around the place, typical in catalog shoots.
The big BUT about generators is when they are not yours or when they are well worked out. When they start choking and giving trouble they are a PITA.