Pros
You work mostly with smart and intelligent colleagues and managers, from whom you can learn. The variety in industries and clients that you may attend to are an enormous booster for your working experience. Also good for CV building and connecting with companies to plan your eventual leave. Initially, its very hard work, but immensely challenging and rewarding. Decent benefits.
Cons
Work-life balance is extremely poor. Long hours and little time off. However, this is wide-spread in BIG-4 and most other accounting/tax/financial services firms. Highly hierarchical organization. It's the Deloitte way, and challenging that is frequently frowned upon. As you rise through the ranks, the exiting parts of executing and managing teams gives way to network building and sales activities. If this is not your strong-suit or not what you signed up for, the only way is out. Starter salaries are low and gradually rise to average. However, this highly depend on the service line you work in. Some pay abysmally, some have decent pay. Again, this is the business model of these type of firms, and not just at Deloitte. You are the product, you are the asset, and pricing is constantly under enormous pressure. Deloitte Mexico prefers to attend a large volume at lower cost, than having a quality first approach. This is not a strategical error at all, but it doesn't make for a great workplace.