Pros: it's not volunteer work
Cons: too many to list here: poor compensation, negative employee culture, few opportunities to really advance--read the review.
There are very few opportunities to move up within Santander. You are more likely to experience upward mobility (both in position and in compensation) by quitting and applying as an external applicant, and I have frequently heard of management recommending team members do this. The employee culture is lifeless. There is no value for team members, from compensation to benefits to employee appreciation. The goals and SLAs across the board, regardless of where you are in the company structure, are incredibly burdensome, and again there is no appreciation for going above and beyond--the tier for determining raises (too complex to explain here) is structured towards those who complete a moderate level of production. Just insane. As a result, the turnover rate is high and employee morale is low. Outside of all this, the systems and hardware in use is out of date, under-powered (think DOS-based systems, and an intranet that crashes constantly--they just upgraded their PCs from Pentium 4's for god's sake!).
I wouldn't consider Santander for anything other than an interim job, definitely not a long-term consideration.