Lets not get too bogged down by this as when comparing specification on bron's top battery and studio packs to Profoto you really are splitting hairs and neither are short on features. However, for me by far the biggest and most important advantage was when I was shopping for powerful battery location lighting (owned and loved AcuteB2 packs for location) I visited a trade show to look at the then new B4 and was shocked and dissapointed by their size. At the same show I then passed the bron stand to which I knew very little about their product range as they not exactly aggressive with marketing unlike Profoto and discovered the Move 1200L. I waved bye bye to all my Profoto gear and the rest is history.
I must say if I was looking for a lighting system before the introduction of B1s, I would have definitely gone with Brons move pack as it's far lighter. But the B1 was really the game changer not only on its lower entry pricing but also chord less and plenty powerful for most outdoor use.
For me I shoot mostly on location so wish to air more lights but yet I still wish to use them in a studio while trickle charging it. That's why i am on the market for b4 or a move. It's true that as many of you suggested I should probably just stick to one system.
Where are you based? I find Bron modifiers are more expensive here in New Zealand.