Short sales (called that because the bank is being "shorted" the money they are owed) should actually be called "Long" sales. I've seen the bank respond in a few weeks and I have had buyers give up after waiting up to 6 months with no reply.
Almost every short sale is sold "as-is". If the appraiser, for your mortgage company, finds a major problem with the home it may stop the sale depending on what type of mortgage you are doing. You, as the buyer, can do the repair beforehand but do you really want to do a major repair to a home you don't own yet? A work around could be to flip to a renovation loan.
Short sales require a lot of communication and paperwork from the seller of the home. Is the seller fully on-board with getting the short sale approved? If a divorce situation, are both spouses going to do what it takes?
I've had two short sales in which the bank countered the offer back ABOVE the list price of the property. This was after both buyers waited over two months for a reply. Both buyers didn't feel the homes were worth what the bank demanded so they walked.
I also had a situation on a property that had two liens (mortgage company 1 and mortgage company 2). Mortgage company 1 approved the short sale but Mortgage company 2 wanted the seller to agree to pay them the full $30,000 that was owed. The seller refused so the buyers had to find another property.
Some real estate agents are making the buyer pay a fee for a Short Sale Negotiation company. This fee can be thousands of dollars. They justify it by stating You, the buyer, are getting a better deal on the home so you shouldn't mind paying the fee.
Having said all of the above, I have had successful sales with short sales and a few buyers that I felt got really good deals.
I hope this is of some help.
Prudential Patt White Real Estate
Lehigh Valley, PA