F2toF1:
choose 1: if I choose a university belong to Vermont service center, I only have one and a half month to change visa type
choose 2: if I choose a university belong to Nebraska service center, I have three and a half month to change visa type. However, I was told this center is very slow.
Choose 3: choose any university above, take a tisk of being sending back to China, to change visa type in Mexico or Canada?
Which one should I choose? Please give some advice and thanks a lot.