I know absolutely nothing about audit. I don't even know what the work actually entails. All I know is what I've heard from countless CPAs, which is that audit work is tedious, monotonous, assembly line drudgery that ends with zero satisfaction in the result. Maybe others here have different experiences, that's just what I've been told literally hundreds of times.
Tax law, Treasury regs, IRS rules, and Tax Court rulings, on the other hand, I am quite versed with. There, you get to constantly learn new nuances. There's the joy of researching for, and finding, a workable solution for your client. Representing a company that's getting jammed up by the IRS, helping to save jobs and small family businesses from the guillotine, that's hugely satisfying.