Pros
Not much really. Perhaps some "stability" but that is an illusion. Layoffs are common indeed. Colleagues tend to be nice, normal hardworking people. Some people are confrontational but most of the troops are quite relaxed. If you are a locally hired, non-"strategic" employee, best compensation is when you get hired because it rides a descending curve. Training is a joke, they give you the cheapest they can find. When there are "important" soccer games, it's ok to watch on the company's tv's (best pro of the company)..
Cons
Only those in the inner circle from their home country, enjoy benefits, generous company perks. All others can expect to get the bare minimum standard treatment. Most of us never get ahead. There are old timers with 20, 30 years in the same position they were initially hired. Salary increases barely keep up with inflation. Very commonly your manager will surprise you on bonus day that your performance was subpar so NO bonus for you that year. This is so because bonus announcement is on the same day you get your evaluation, so you have no opportunity to defend your point of view. Since promotion criteria is based solely on your origin and being inside the circle, management is incompetent, unprepared, untrained, egoistical, simply horrible. Even externally hired managers tend to be incompetent. Company is pretty cheap. If you are a "commoner", don't spend a dime more than the bare minimum when they send you on business travel. You won't get reimbursed. Walk or take a bus if you can, don't take a cab. Top management from hq is also horrible. Spain is broke.