Vantaggi
Deloitte looks great on your resume when you decide to leave. A lot of your coworkers will be bright and ambitious and if you decide to drink the Kool-Aid and make a career of it, there's certainly good money and a lot of resources -- great parental leave, paying for graduate degrees for selected candidates, etc.
Svantaggi
Deloitte's strategy for experienced hires seems to be 'give them a major demotion in terms of responsibility, put them on a project that's not related to their background, and wait for them to leave.' I had experience with consulting an internal labor markets before and I'd never seen a system as dehumanizing and uncoordinated as this. Additionally, and I assume this is because Deloitte bases what level they bring you in part based on your current salary, I saw a lot of mid-career women who had kids being brought in at very junior levels, but very few men. The lack of flexibility in various ways is also particularly tough if you have small kids. On top of your client work/utilization expectations, there's the expectation that you'll be going to networking events and doing PRD. That took me away from my family without building skills for me that were useful outside of Deloitte. In general, Deloitte is very geared at getting you to do things which are useful for Deloitte and possibly useful for your career while you're at Deloitte, but not useful at all if you leave, which you'll probably do within a few years of joining, anyway.