I've been accepted to two universities for M.S. programs, both with funding as an RA. One university is ranked within the top ten in the country for geosciences. The other university is a lesser ranked state school, but it still has a good program for my research interests.
At the top ten school, I would probably be my adviser's only student (he has a few PhD students who will be finishing either this semester or in the fall); however, after speaking to his students, some expressed concerns about being advised by him given that he is rarely available (often not in his office, travels a lot for leisure, doesn't respond to emails, and sometimes has a short temper).
At the lesser ranked state school, I would be one of eight students in my adviser's lab. The students there seemed generally satisfied with their adviser, even though many mentioned that he is very busy, given all of the students he has. I received a good sense of lab group community and that the students worked together to help each other. The adviser also has three post docs (one of which who was identified to help mentor the students who are working in my research area).
I know one school has a much better ranking than the other, but I'm concerned about potential issues with my adviser at the top ten school. Students do change advisers after arriving, so that could potentially be an option, if I am having issues; however, it could be stressful to have to find another adviser who would choose to supervise me and has funding for another student.
I would appreciate any feedback/insight from anyone who has had to make a similar decision. Thanks!