I did not graduate from the Graduate program, but I studied there as an undergrad and got to know the students and the program quite well. I took a few of the masters level courses as well. The program is good because it has a few really smart hedge fund people working there. Take a look at the profiles of the professors. Everyone knows James (Jim) Simons, and they also have other really great practitioners, and are hiring more, so the program is developing.
However, most of the good news ends there. I studied with the masters students there, and they sadly, don't get jobs. Half of the PhD students have a good internship, and there are an abnormally large amount of PhDs for a program of its size. (About 12 last time I checked). Career services is no help, and Stony Brook isn't really a target school, so you will have to go find your own internship, or start your own hedge fund/prop firm (which is almost a culture at Stony Brook QF). That being said, Stony Brook's program is quite different from the programs of others. The courses it offers are not that demanding, but there are a few interesting ones such as "Important Papers in Quantitative Finance", and "Case Studies in Quantitative Finance" what you won't really see elsewhere.
The courses themselves are foolishly easy. However, this will be to your detriment when seeking jobs and going on quant interviews as the program lacks rigor when compared with the top quant programs, and the culture there isn't extremely motivated. You can see many of the alumni have tried to work for startups, or went in completely different directions (other than quant finance). You will however, be getting a bargain as Stony Brook tuition is extremely cheap.
The program is not selective at all. I know a stock broker who had no math background at all that got in. 99% of the masters students are Chinese, and don't speak English well enough to pass an interview. I spoke with the director of the program about this one day in his office, and he said "Honestly, I feel sorry for them. They won't really get anywhere."
That being said, the top 3 or 4 PhD students are doing really really well. If you can become one of those people, then you have a chance to do something with your life. I also know one Masters student who is currently interning at CME in New York. That's it. After graduating from undergrad, I felt like I really needed to get out, so I went to a different quant program, and my oh my, there are leagues and leagues of difference between the program I am in now, and what Stony Brook offered me.