F2-F1 Change of Status

I am currently in the US on an F2 visa and got admitted to my masters program for fall 2020. I am still debating whether to apply for an F1 visa overseas or apply for change of status while I am in the US.

My Question is: in your experience, how long did it take USCIS to process the change of status from F2 to F1? I know it varies by the processing center. Can I choose whichever processing center I want?

Thank you!