Pros
You work with smart people- there is a comraderie in being underpaid and overworked. The work was often fairly interesting, and what you did mattered- you learn that all too well the first time you make a mistake. Its easy to get promoted. If you are reasonably competent, you are pretty much guaranteed to be a VP in 5 years!
Cons
Stress is off the walls. In the algo trading group, you have billions of dollars pushing through your systems every day. Thousands of boxes, dozens of strategies, tons of connections. So much can go wrong. Yet the pay is mediocre- most guys on my team did not get a bonus or got a token bonus (under $3000) in the previous 3-5 years. The IT division is 70% consultants. The consultants get paid on a day basis, so that means the remaining full timers get stuck with all the weekend work because they don't want to pay consultants. So if there is some kind of release, server upgrade, network change that needs to be verified, its all on the remaining guys- and that 30% that is left also includes managers, who won't be joining you on those calls. The red tape is torturous. On one side you have your managers and business counterparts who are all over you to get a change out, and on the other side you have this vast machine who is pushing hard against you to force you to fight to get it out. Every year there is a new excuse as to why the bonuses were non-existent. ROE is too low, Earnings are up, but revenue isn't... its all a bunch of BS, IT is a cost center, and they aren't getting paid, regardless of whether you are some kind of server monkey or in the front office writing strategies.