Good lawyers help.
What also matters is what group are you fitting into. Having a diploma which is evaluated to Master Degree of American university speeds up a process significantly. Process with Bachelor Degree is pretty slow. There is also an extra quota for those who have American education. And the process is much faster for those ones.
My EBGC process took about 20 months for the whole family. It could be faster, but I had to reschedule fingerprint exams for 2 or 3 months, being out of the country. My lawyers were pretty expensive, but they are much worth it. :) I have MS of CS from foreign university. It was evaluated to the Master Degree. I also have a bunch of certificates, but I don't think they play any difference.
Originally coming on H1B for two years and H2 for the rest of the family, I didn't have to prolong it and I also didn't use advance parole and work authorization (although, my lawyers made them for me).
I'm working for a pretty small company (less then 20 employees). My original position was not anything special, a regular IT fit, so I don't think it matters.
I have spent a lot of time learning the whole process and one of the most important concerns is the lawyers. They can help or they can kill.
Feel free to drop me a message to w at qwe3 dot com if you have any more questions.
P.S. I have a friend in SF waiting for his EBGC for almost 6 years now. Nothing, yet.