Pros
RAND has an opportunity to get a PhD and be a RAND researcher at the same time. The catch is that you pay $16,500 out of your salary in tuition every year regardless of whether or not you actually have time to take classes beyond your required coursework in the first two years (spoiler: you won't have time to take classes). Pro's: you get to work with really smart people on a variety of interesting projects and you will learn a lot. This is a good opportunity if you are early on in your career and the opportunity cost is not too great. Otherwise, it is a bit of a money sink and you may be better off learning on the job at a place where you are being paid as a full time employee.
Cons
Con's: Tuition is creeping upwards and $16,500 out of your annual paycheck even if you are not taking classes or using ANY school resources is already steep. Billing hourly is a pain, and you will not feel like a "student" in the traditional sense with the freedom of time to choose your own learning. Rather you will more often feel like just an underpaid RAND employee.