F1 is faster than F2b for "other countries" based on the visa bulletin, but as of March 2013 not by 4 years.
F1 for March 2013 is Feb 06 while F2B is March 15, 2005. At that rate it's faster by about a year. But the PD changes every month based on the visa bulletin.
It depends on the priority dates for the country of chargeability.
The movement of priority dates cannot be predicted.
For the latest visa bulletin see http://www.engnishimura.com/priority-dates/current
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.
I agree with my colleagues. Sometimes upgrading a petition works to get residency faster. Other times it is best to stick to the category applied in. It all depends on your priority date, category and what numbers are available under a particular category.
This response is general in nature and cannot be construed as legal advice, given that not enough facts are known. Any comments offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship. If you would like additional information based on this response, please contact my office at 510 657 7665 or 415 902 0832 to schedule a consultation.