Vantaggi
Penguin has a good reputation and a lot of talented editors, so there are opportunities to work on interesting/high profile projects and the quality of work is high. Editorial staff here learn a lot and make important contacts. Depending on your immediate supervisor the atmosphere is relaxed and the benefits are good.
Svantaggi
Many of Penguin's practices are antiquated - even for the generally old-fashioned publishing industry - and instead of helping productivity end up creating busy work. Promotions are slow in coming and happen haphazardly. Many editors are frustrated by publisher and management decisions, but there is no way to communicate dissatisfaction or problems within departments to higher level supervisors. There is constant pressure to publish "commercial" projects and to steer away from "literary" titles, and you can expect to work late or on the weekends a few times a month.