BIG-IP AND NG FIREWALLS POSITIONING BEST PRACTICES

totally agree with above answer, it depends.

you need to look at the total picture. what is happening on the inside and outside of the network?

in general i would expect a big-ip to handle heavy traffic a bit better then a firewall. but with a virtual edition that changes things. on the other side if you have a smaller internet connection that becomes less relevant.

with virtual edition you expose your hypervisor in a certain form to the internet, something to think about.

so yeah, there is no best, you have to think about pros and cons.