Pros
It is a great environment that you meet some very intelligent people. Has access to state-of-the-art facilities and equipment, good benefits... and this is all you get out of them.
Cons
This review is just from the perspective of someone who started as a postdoc and was promoted to the level of Research Scientist. It probably does not apply to other positions. By the name alone it seems like an institution that will open a million doors and will give you many opportunities. Well it is not. That is the elaborate trap that sucks in hundreds of postdocs every year. As a results we join in and we are called to live in a city that the average rend is 1500 for a studio with a scary of $45,000. And somehow we manage. Our savings (if we have any are exhausted) by the 25th of the month we have no money for food and on top of that we are called to work late nights weekends, holidays, snowstorms and even when the city is in lockdown. And this is doing a conservative life. Imagine this now, but also being naive that you can start a family. Who you think you are? Start a family? Oh no... Absolutely no. I have one. I work as a line-cook to a restaurant to get by. Guess what/ My work there is recognized a lot more. I get paid a more compared to the hours I put. And things get worse. Harvard has a series of elaborate schemes to feed the illusion they promote that you are "advancing your career". They tell you that we don't keep postdocs here for more than 3 years because "it is not good for you". Instead the promote you to "Research Associate" to advance your career. What they don't tell you is that you are still a postdoc that will still be overworked and underpaid and you will only get paid 5000 more. Yes this is it folks! PhD 3+ year of postdoctoral experience and you get $50,000. What a job! Who wouldn't want that. Here spend the rest of your life like this. I call it modern day educated "slavery". We are there because we love what we do. We are willing to pay our dues, but at the end of the day it is coming to doing what we love or living decently. The PIs are keeping you to help them and there is no interest to advance your career. It is all about them. You get nothing out of it. Well you get 50000. You are mid thirties living with a roommate, no prospect of family and no prospect of promotion. Harvard Administration does nothing to protect us from this. They willing look the other way and allow this perpetuate. Postdocs are highly trained, results producing machines that are used, literally used, to promote faculty. Went he money runs out you are just out. No interest in what you will do, no care and remorse. It's on you. It is the worst place to work in academia. Even if one prospective postdoc reads this and is protected then my mission is done. Please don't come to this hell on earth. Protect your rights, your life, your family, your mental health and your career. Please do not come.