We are closing (hopefully haha) on a REO wholesale. They are a pain in the *ss to deal with the paperwork on. The legal paperwork the seller/lender put forth upon accepting our offer was about 4 pages, which basically said 'we agree to whatever the seller says, and no matter what our P&S says, the addendum shall control'.
The bottom line; REO's seem to take longer than typical wholesales. They are worthwhile (this one was a list price of $83,900, FMV $135,000, needs about $25k in repair, our purchase price is $32,000. This deal has taken us about 6 months to get to this point.
Best advice: get a good Real Estate atty involved early on (as soon as the seller accepts your purchase price). A good Real Estate atty can start handling the legals early on and save you a lot of time.