In my experience...
...F5 compiles and runs.
According to an IT man from Arizona, F5 is up to something, something good. We've been wondering what it has been doing now that it has acquired Acopia and its file virtualising ARX switch. Well, according to this Arizonan who is familiar with the situation, F5 is developing a single box to replace two that people would need now …
F5 are lamers that run on redhat and sell people products that you can make yourself for free with a linux box. Take BIGIP which you could replace with Ultramonkey.
This product sounds a lot like their Wankjet product which is basically nothing more than a reverse proxy. You could set this up with squid or even apache's mod_proxy but you could also make a bunch of septics richer by buying an inferior redhat based product.
Oh and then theres the "technical" support... which is about as technical as my grandma as most of them dont have a clue how their own products work.
In short, dont buy F5, get a linux box and read tldp.org
Lest you all forget, F5 is the "brains" behind phorms crap.
The BIGIP platform is loosely based on RedHat but most of the traffic management is handled outside the Linux parts. Also, Ultramonkey et al are great for plain load balancing, but once you want to do something funky with the traffic BIGIP gives you an easy way to do very complex stuff. Perhaps you can't imagine a need for it, but there are people who are prepared to pay muchos dineros for that kind of capability.
But yeah, they're still overpriced.