Pros
First disclaimer, there is a vast, vast difference between commercial (working for private companies) and federal (government agencies). The two are extremely segregated and cross over is very difficult. Great Benefits, especially the leave plan. Deloitte allows you to "charge" time for military service and offers compensation pay for activations (meaning they add extra to your military pay so you still get paid equivalent to your normal Deloitte salary). More leave is offered than you could hope to every take (on the Federal side). Good 401K contribution matching and miscellaneous benefits (family leave, legal plan, etc). Deloitte has a pretty good professional counselor system (usually someone two levels above you) and great networking opportunities internally. Pay is top rate when compared to other federal contractors and even local private firms. Excellent growth opportunities, they will pay for most certifications or training and for license maintenance.
Cons
The evaluation system is poorly thought out. You are evaluated primarily on the number of hours you bill towards client work, however the "standard" is above what most federal contracts will allow you to bill, let alone time you take for a vacation or internal firm work (more on that in a second). So in the end, most practitioners are in the hole at year end evaluations and are constantly struggling for a new opportunity. The firm has a over emphasized internal contribution aspect. Developing proposals for new work makes sense as revenue growth, but leading firm initiatives and "Business Resource Groups" amounts to not much more than busy work. Often committees are created solely for position titles and I would hazard that less than 20% of internal initiatives are tied to new revenue generation. The number of hours tagged for these internal projects is also pretty excessive. Keeping in mind that in order to make the metric I discussed above you have to be on client site from 8 to 5 that means that you need to then drive to a Deloitte office and put in another three to five hours a week for internal projects of little perceived value. This seems to work fine for our Analysts just out of college, but for senior practitioners with families the work life balance is pretty tough. The Federal practice also operates in much the same way the government does, as an insiders club. Attaching yourself to good Partner means your career will be fine...until he isn't part of the in club anymore. All of the above requirements are essentially waived for those who are attached to partners with important firm clout. Business as a federal consultant is pretty tough as well. Remember, the government isn't hiring you for the same reason the private sector is, to get something done. They are hiring you to fill a slot or as a staff augmentation. You will almost exclusively work for people who are more poorly educated, possess fewer soft or technical skills, have little to no management or strategic insight, and who usually resent you for being a contractor. It is not an exaggeration to say that most of my project staff (I am a project manager) have masters degrees while only two of our GS staff have college degrees (most are highschool grads). Yet we work for the GS staff and take direction from them, contractors "leading" initiatives is highly frowned upon (it can be a union violation). If you are looking to get a sense of accomplishment by seeing an organization or process change, try the commercial side, the federal side is primarily concerned with budget justification. Overall, I would sum up the cons as: "unnecessary, extremely burdensome requirements, for little benefit, that is detached from how the firm actually makes money, which itself is somewhat unsatisfying."