Pros
Some of the security work is interesting, especially if you are a fresh college graduate and just starting off in the security space. A few of the senior analysts and developers are smart and good to learn from, and you will learn more from the real world assessment and development work then you will from any lab environment. I would recommend ISE for a fresh Computer Science college graduate interested in getting some hands on technical security experience.
Cons
ISE has many issues. First, the CEO is never present, he does not communicate well, and he is not an effective leader. He rarely attends meetings or provides any direction or true leadership to employees. He's mostly hungover at work if he does show up. He is also known to become easily angered and yell at employees. The company has very little concentrated direction. There are always pet projects that lead to zero business generation and limited to no actual revenue. These pet projects take away from time that could be used to drive more billable work. The day-to-day analyst work is lead by childish senior analysts who make sexual innuendos and "that's what she said" jokes during company wide meetings. Majority of the individuals in senior positions are certainly aware of the companies lack of direction, but are just on-board to take advantage of the CEO, who is oblivious to it all. Several senior managers / directors perform little to no real work to drive or support revenue, yet have convinced the CEO they are a necessity. This all makes for a very unprofessional environment with no clear direction or values.