I bit the bullet and bought myself an Elinchrom Ranger Quadra pack recently. As much as I love off-camera lighting with speedlites they often are not powerful enough limiting how much ambient light you can cut out. You can add some seriously cool modifiers to the Elinchrom heads too! Although the speedlites are a necessity for some photo jobs these studio style strobes are really good for creative lighting when you have a bit more time on your hands.
The battery pack is 400W and I opted for two heads though I will probably have to add another pack at some point because of the cables and the Asymmetric function of the pack - meaning power is split 66% to one head and 33% the other. The whole set-up is incredibly light considering how much power it gives out - 2 stops more than my Canon 580EX - and pretty easy to set-up. Added bonuses include changing power settings from the transmitter on camera and the modelling light which might come in handy for video stuff.
When they arrived in the post I headed out to give them a go and had to settle for photographing myself on a cold winter afternoon with a timer, very happy with the results though! A head up high camera right on me and B head low camera right lighting up foreground.
