Your experience may vary. I was fortunate enough to be placed with two excellent clients and a manager who was a perfect fit for me. My time at memoryBlue would have gone very differently if I had been placed with a manager who wasn't as willing to work with me or if I had been placed with a different client. memoryBlue works with a lot of startups and every SDR, essentially, works for one (or two) of them. Obviously, some startups are better than others, so some people get stuck with duds. I don't know if there is anything to be done about this - my guess is that it is unavoidable and that other, similar, companies are likely to be in the same position. It's just something to be aware of if you're considering joining the company.
Note that most employees are coming directly from college and the workplace reflects that. Not necessarily a con, just something to keep in mind if you're a bit older than that.
There should really be an "observations and comments" section because, again, this isn't a pro or a con. Just note that I am a straight, white, male and that my experiences reflect that fact.