Grad school - Is transferring to another school for a Master's program (Computer Science) a good option?
I think you should stay where you are. My thoughts below.

Research. At the beginning, the classes seem hugely important and there is a lot of angst about whether you are at the "right" grad school. By the end, the only thing that matters is your research. 

You write:


  Fortunately, I am working with one of the best profs the university has to offer on a very impactful project and the research is going great. But that's the only plus point I see from sticking around.


This may be the "only plus point", but it's the crucial one. If you're doing good research, learning something, and publishing good papers in good journals, then your PhD is going very well.

Rankings.
I think you would have a legitimate concern if you were at a predatory grad school that no one had ever heard of. But you say your school is ranked ~50, so presumably it's a "real" school that people have heard of. Going to a "slightly" better school will make ~no difference to a hiring committee. Going to a famous, top-10 school might make a difference, but even that is maybe less than you imagine.

Other students. I would point out that it's not necessarily that the other students are dumb; it's that they haven't covered this material before. But even if they are dumb, that just makes it easier for you to get the resources you need. One of the best talks I ever attended was from Karen Kelsky, who made the point that hire-able grad students are able to "pass" as a professor -- in the way they dress, the way they interact with colleagues, and the work they do -- so the other students are really irrelevant here, your "colleagues" are the faculty. 

Time. I would also consider that transferring schools is a lot of work and, if you start from scratch, it will mean wasting a year of your life while you repeat "year-1" of grad school. Grad school is worth taking your time and doing well, but I would also seriously hesitate to lose an entire year -- you only get so many years in the workforce, so an extra year in grad school means one fewer year in the meaningful, interesting job you'll eventually find.

That said, I admit that getting a degree from MIT or Harvard would be exciting. If there's a way to apply to such schools without burning bridges, it might be worth sending in an application "on a lark". If you get in and have an advisor lined up, then I might even consider switching. But I would remain fully committed to your program until then -- it seems like things are going fine, and there are definite downsides to transferring even to a top school. Good luck!