UWashington vs. UC Irvine vs. UMichigan for PhD in Information Retrieval/AI

[crackd]

UC Irvine & UMichigan both accepted with fellowships, and U Washington pending. UW is my top choice due to ranking, location, and the small bit I know about their program, but Irvine and Michigan are close choices.

My interests are with information retrieval involving large scale database systems, along with artificial intelligence/machine learning with that data. Bioinformatics is also an interest, but not as important as the other areas.

1) If UW w/ fellowship (full tuition + monthly stipend) as Irvine and UMich have, which to choose?

2) If UW has less funding, which to choose?

3) If UW rejects, worth working for another year to wait for UW?

4) Any other schools I should consider (Stanford & Berkeley rejected, which I understand are great for these areas)?