We used it in both of my graduate micro classes and it made me want to hunt Hal Varian down and personally thank him for not torturing me with his Micro book. If you're reading Mas-Colell for fun you need to commit yourself to St. Elizabeth's immediately. Seriously, everything about this book is torture - the material, the font, the book itself (it weights around 4lbs).
I'm going through my notes and it (Mas-Colell) again for a refresher before my interviews start. Good thing most of these jobs are straight econometrics, I don't think I could handle having to spend that much time obsessing over utility functions. Instead it'll be variance inflation factors, differential item functioning, collinearity, and logit models. Lucky me.
I can't comment on the book itself, but I always found economics generally to be a fun and enlightening field of study. Maybe when you are an accountant, that's a matter of perspective.
I had 15 Econ hours in undergrad, another 6 in grad school, it was a relief from the accounting stuff at times.