First, big congrats!
I would choose MSU for two reasons:
1. I think MSU is stronger in development econ. OSU gets several good faculties in development econ, but the department is more focused on Environmental and resource econ.
2. Though life is easier without doing any RA job lol, I would think RA job as a good preparation for publishing papers and working with professors. And obviously recent years job market candidates from MSU get more publish than those from OSU.