I have always had good luck with US Bank. The most important thing is to make sure the file is in the right department and on the correct platform. meaning make sure if its a short sale that it is processed as such and not stuck in loan modification
Getting an answer from any bank takes time and the better the offer with the least contingencies the better, but it will still be a while if yours is the first offer. The only short sales I have done in 2 months or under were ones where a previous buyer backed out tired of waiting for answers and I moved in with a new buyer.