Did you know...
The Profoto 8a Air (2400Ws) delivers only 1000 full power flashes an hour?
Yup. That's 16.67 flashes per minute. So even though it recycles at 0.9 seconds, it can't be abused consistently at 60 full power flashes per minute. At 16.67 flashes per minute you're averaging 3.6 second delays.
Why? Because each pack (and head) has a maximum continuous usage. The Profoto 8a has a maximum continuous usage of 40,000Ws per minute.
So what's the Zeus Z2500 (2500Ws) maximum continuous usage rating?
The Z2500 pack (and head) has a limit of 30,000Ws per minute. That's 12 full dumps per minute (remember it's full power is 2,500WS and not 2,400Ws) so about 33% less maximum continuous usage "capacity".
I'm guessing beyond 12 full dumps per minute and you trip the built-in breaker on the Z2500. Same goes for the Profoto 8a but you get almost 17 full dumps.
See my previous post for spec comparisons including price. Let's just say there's about $10k+ in price difference.