Pros
Training was good on an overall level, such as for the Tax code and concepts. Having the firm's name on your resume is absolutely required by some companies in and outside the industry for employment at higher, more senior levels. Management has a very high technical competency. Promotion is based almost exclusively on that particular factor (note mention of this in the "Con" section as well). The number and level of benefits is high, as is generally common for the industry.
Cons
Training on basic applications, such as proprietary software, and industry-standard software used by the firm was essentially non-existent. Managers generally have little or no interest in training new staff; the general attitude seems to be "sink or swim." As noted in the "Pros" section, management is very technically competent. Unfortunately, this is virtually the only factor considered or valued. People skills, training skills, and basic general management skills are, at best, considered irrelevant; at worst, they are looked down upon. Due to the nature of the industry and the personality types which are most suited to the work (especially compliance work), it is quite unusual to have both the necessary technical competence and people skills in the same package. Criticisms of work performance are frequently presented in hyperbolic terms, and can be startlingly personal in nature: "careless", "sloppy", etc., are frequently and casually thrown around even when there are a small number of insignificant errors. Accounting firms, especially Big Four firms, are known for a "churn and burn" culture: departures are frequent and tenures are not normally more than a few years. Due to a steady influx of young (and naive) students, there is very little impetus for change in the work culture. As an example, KPMG just recently allowed employees to begin wearing jeans on "casual Friday", more than a few years behind the curve.