Pros: none really, cost of medical, salary, culture and all things considered; there is a free vanpool to ensure employees get to work.
Cons: high cost of medical, very low number of sick days, average compensation
PACCAR is a firm where an engineering degree whether mechanical or electrical "gets you in the door" but after that you'll never use any of the education you learned in you engineering studies; say for example your an EE, forget about PLC's, VFD's, LT Spice, Matlab, Simulink, Labview. Yes it is true that some engineers will find their way and can get a niche job doing Labview at PACCAR's PTC tech center, for the majority what you learn over time is how to answer the phone (when dealing with cross functional silos), set up meetings, answer missed BOM calls or work orders known as REI's. Work in the industry a decade or two at a commercial truck manufacturing firm and go look for work as an EE elsewhere and you'll find you won't be able to call yourself an experienced EE as "power systems, high voltage power, three phase, etc" things that are expected of Senior engineers just aren't things you'll do here. You will need to be good at presenting in meetings, creating powerpoint presentations and supporting the truck manufacturing plants. The overall morale at PACCAR is low at times due to the culture at PACCAR where employees are asked to do something they might not like to; such as come in clean shaven as the perception that engineers look a certain way is enforced. Pay at this particular employer is only average. Opportunity for advancement exists as long as your manager likes you. PACCAR is a great firm to gain intern experience and then you can decide to leave while I would not recommend it as a dream employer firm.