Vantaggi
UBS is one of those companies where it's so big and there are so many different types of environments depending on where you are located, your job function, etc., that it's tough to broadly characterize benefits to working here. In a crude attempt to do so however, I'll say that this is a great place to have on your resume. It has international recognition, experts in several finance-based practices work here, and it is a fine place to grow/develop or move on from.
Svantaggi
When morale is low it is LOW. I worked here at the height of the financial meltdown and things were very bad. People were cynical and had bad outlooks about their position in the company. The company also gets a bad rap from client tax scandals, taking bailouts, and poor investment practices. That being said, this may not be unlike so many other large Wall Street players that have problems of their own.