Pros
The best reason to work for ZS Associates is probably the laid back work environment. It is a very friendly place to be. Your co-oworkers are, for the most part, great people who want to help you succeed and be happy. Jeans and a tshirt are acceptable work attire (though jeans and a polo shirt is probably the typical outfit. Sandals are not frowned upon though if you want to be a go-getter you might want to wear sneakers just to be safe. Average age is probably around 25/26 so its a young, fun group. Its a good place to work!
Cons
Probably the biggest downsides are: 1) among those who dont work in the healthcare consulting industry Z S is not very well known so its not as easy telling people where you work as if you worked for Bain or something. If you are looking for that name recognition and brand awareness from others this is probably not the place to be. 2) Compensation is fair/solid but I wouldn't say its "great." 3) despite their best efforts to help you with work-life balance, its still consulting and that can suck up a lot of your time ... there are late nights.