Pros
Nice colleagues. Also if you're from abroad, they will probably sponsor your visa, so even though they will treat you like a stupid foreigner willing to get paid peanuts, it might be worth it for a couple of months.
Cons
They lie to their candidates promising amazing in-house projects for big companies, saying that you will be working in their nice office with all that amazing vibe, that your salary is fair and that everything is amazing. In reality you will be sent permanently to the customer's office where you will be some sort of second class employee, with worse conditions, getting paid way less and doing the same work. Not to mention the extra commute! (some people is even commuting every day from Amsterdam to Eindhoven!). If you're still interested, make sure not to schedule your interview on Friday to see the real deal, on normal weekdays the office is empty and quiet like a cemetery, everyone is working on site for the customers. The office is for the manager army and their expensive company cars (all paid by you!) Also pay attention to the fact that there's virtually no dutch new joiners. That's not a coincidence, no skilled local that knows the market would work there knowing what you can get somewhere else. And if you're crazy enough to even consider signing with them, pay attention to the "non-competition" clause of the contract; you won't be able to work directly for the customer where you were placed if you like it (they will refuse), and even the clause itself is illegal under dutch law (good luck fighting for it on court, as the customer will not burn bridges for you). Besides that: HR will make random deductions from your salary, where you are placed is where you will stay (no development / salary raises), insane rotation, rumors about financial trouble, and lots of lies on everything.