Pros
UBS is one of those companies that will probably always be around. I worked for them as a Regular employee (what many call "permanent," although we all know that's a misnomer) from 2005 to 2008, and they were always very good to their employees. Great benefits, generous vacation time, good pay--even an onsite company fitness center with yoga classes at the low cost of $40/month which was automatically deducted from your paycheck. I returned to UBS as a contractor from Jan. through May 2011, and left for a regular role elsewhere. I would have liked to have stayed at UBS if they'd been able to place me at the time.
Cons
Sometimes management can make poor decisions, as in the case of hiring the former Chief Communications Officer who was in place from late 2010 through May 2011. This person was so scattered that the Global Head of Communications got on a plane from Zurich personally just to fire her. Unfortunately, during her short tenure, the firm lost a lot of invaluable institutional knowledge when a number of key communications people walked out the door due to her inability to lead. But since that problem is now in the past, no cons!!