Also consider this:
Let's say you need 2 500 W/s monolights for the shoots you want to do.
Option 1: Buy THREE Einstein (same company as alienbees) that go up to 640 W/s, 9-stop range, down to 1/13,000th second duration, 2,000 full power shots per hour, color constancy, 1/10th stop control = $1,500
Option 2: Buy TWO Profoto 500W/s lights, 7-stop range, down to 1/2600th second duration, 1,500 full power shots per hour, color constancy, 1/10th stop control = $2,400
Option 1 gives you actually more utility and flexibility in the lights' options, because Einsteins can simply do more. AND saves you $1,000. The potential drawback is that maybe the build quality is not "tanklike." However, notice that I wrote "THREE" Einsteins. Even if there's a slightly higher chance of one breaking than the profoto in the middle of a shoot, you just whip out the backup and keep going. Then send off the other unit to the company whose excellent customer service should sort it out with you like everyone online says they do. In the meantime, just use your other two units, in a week or two, you're back to having a working backup. A scenario which frankly is likely to never happen even once on average, but if you demand high reliability, you have peace of mind and still save lots of money and get more flexibility.
In fact, option 1 gives you MORE reliability, because unless profotos are made out of adamantium and unicorn blood, the chances of having TWO einstein units fail at the same time (necessary to stop your shoot) is guaranteed lower than one profoto failing (which also stops your shoot). In order for this not to be true, it would have to be some ridiculous, like, 50x more likely per shoot to fail or something for the Einsteins, which clearly isn't remotely true.
Why would you not choose to simultaneously get:
* Higher reliability of making it through each shoot overall
* 40% off the price
* ~5x better motion freezing ability
* faster recycling
* more power
* more range
Well, again, maybe if you're carrying your monolights up a mountain, profotos might be a better choice. Otherwise, I suggest they are not.