go with bigger fields and more tourneys. less people means less paid as well. u wanna score big in mtts, and its easier to do so in bigger fields. say u make FT 3 times out of 50 runs. If u play small gtd tourneys, u might not make money even, or make little. If u play huge fields, ur 3 FT could easily be big scores.

id go with more traffic given such, but thats just me. I think an argument could be made that smaller fields means lower variance and higher return on good play. so i guess its up to you.