What is the fine line between doing excellently and trying to be a perfectionist in the context of big law? I think you want to do the best you can, but, yeah, in big law firms, your work does need to be as good as it possibly can.
One thing I would say in terms of perfection is, your work needs to be proofed to the maximum extent you can. So you always want to make sure you proofread your work as carefully as possible. When you turn things in, and that's very important, when you turn in even memos and things to partners and so forth, it's very important that you do a great job with stuff.