Pros
There are so many pros to working at F5. I would say that the top of the list is the company culture is one of integrity, and one that values the employee as a human, not as a cog in the machine. The Salary and benefits are amazing. I have full family health insurance that is 100% paid by F5. I do not have $ taken out of my check for the premium. Stock grants, ESPP, 401k matching, donation matching, and vacation time are at or above what I consider standard for the Tech industry. Did I mention "Beer Friday"? The company is growing, and that means career opportunities are plentiful, F5 is very consciously protecting the company culture even though the company has doubled in size in less than five years. I've been at other companies where rapid growth destroyed the company culture.
Cons
F5 is growing at a rapid pace and some of the backend systems have yet to be upgraded. But hey if the only real pain I have to experience is struggling with an antiquated system to request PTO then I'll deal with it.