Pros
I worked at a certain "aerospace" site. Consistent hours, decent pay. I thought the account manager was awesome, and so was her replacement. Most of the employees were pretty good, with some definite exceptions.
Cons
Company did not pay for licensing renewals or firearm qualifications. Shift work - poor work/life balance. Poor benefits (3 sicks days a year, per state law). All to be expected in this industry. Uneducated supervisors (some were actually illiterate). Anonymous "alert line" that turned into a way for employees to anonymously attack one another at times. Gender specific grooming standards that were based on your ASSUMED gender. For example, the employee handbook at the time made it clear that males could not have facial hair without management's approval. No such grooming standards were listed for females. The corporate culture is overall very hostile to those who are gender fluid or non-binary, as is evident by their grooming standards! Unhealthy client relationships. I worked at a single SCIS site that required lots of training and specific knowledge. Although I worked for "SCIS," your work is really determined by the contract/client. SCIS takes a "customer is always right" approach, without boundaries. One big problem is that the client is not licensed and regulated by CA BSIS - the guards (and company) are. Just because the client requests it, does not mean it is within the scope of the BSIS license. Also, the client, not SCIS, was truly in charge of personnel management, including disciplinary actions. The mood of the client's security manager dictated morale.