I had a very similar decision to make. For me it came down to Oregon State University vs UC Berkeley.
Oregon State is fairly small (when compared to my current school which is the third largest university in the country) and the graduate program is also very small (currently 11 students), but the research is more interdisciplinary and it is still rated very highly for the program. I have to teach, but it will only be for 1 to 2 years max. I really like the advisor I have there and the entire atmosphere of the campus, grad program, and surrounding city were amazing. On top of that, I love the outdoors and hiking and backpacking so location-wise it is beyond ideal.
On the flip side, Berkeley is the top program in the country and many of their faculty members (including the advisor I was given) have published in top journals (e.g. Nature, Science, Cell, etc). However, the advisor is super demanding and micromanaging and I would have to be a GTA every semester of grad school acting as the primary lecturer for classes of undergraduates. While the stipend at Berkeley is VERY high, the price of living is also high and I would have to make a lot of compromises overall.
I ended up choosing Oregon State because while rankings and prestige do matter, I need to be able to find a work-life balance that allows me to be happy. Additionally, I will learn many of the same skills there as I would at Berkeley, plus other skills like computer programming or analytical chemistry techniques that I wouldn't get because the program at OSU is so much smaller, so inter-department collaboration is necessary. At the end of the day the deciding factor was what would make me the happiest and make grad school the most bearable over the next 4-6 year of my life (i.e. environment).
I know my situation is a bit different but I hope this is somewhat helpful!