I did not file I-485 at the same time of I-140 filing. Instead, I filed it (with EAD, AP) for myself and my wife in July 2003 (still concurrent by definition). So, my hypothesis is that they were reviewing my EAD and AP applications. However, to prevent frivolous filings, they also looked at my I-140 petition to make sure there are at least some merits in my case. I guess I was lucky and they approved it right away instead of returning my I-140 to the queue.
On another note, I do not think the rank of university matters much. Honestly, I consider my background weaker than many people who post in this forum. I don't have many publications (I showed them the acceptance letters/emails from the journals), let alone citations. My two memberships are those anyone can enroll as long as they pay the annual fee. None of my references is famous. Three of them (including my advisor, an assistant prof) are professors from my university, two are associate professors in average universities, and one is my boss (Ph.D.) in the company. I am thankful that they did put out some strong words for me and I made those words very clear in my statement. So, I think the key is presentation of your case. The package should be organized in such a way that make people can easily see you "extraordinary abilities" rather than looking for them.
Hope this helps.
-Brian
