Whichever is the metric for the task at hand, be crystal clear that it is freakishly rare to have both.
Whenever the answer is “yes, accuracy matters”, then don’t work to be fast. When you drive at 60 mph, you can’t turn into your driveway. Accept that and don’t think you can. Let go of the notion that speed matters. Getting in the right driveway safely is what matters.
On the other hand, when you say you’ll call someone right back, that is likely not the end of the day or worse, tomorrow.
Would you prefer a fast meal or a well prepared meal? You have choices just as the restaurant has choices and builds its business around what it actually is willing to commit to perform. Doing your best work is about making it great. Being fast is about putting something out there quickly.
Both fast and accurate are measured against two variables, your promise and the market or individual expectation. How many clicks you are willing to invest for the website to get you where you want to be is a matter of how important getting to the right place is. How long your client or prospect is willing to wait for the return phone call or the promised proposal is up to her. How quickly you can produce it at a particular level of quality is up to you.
Make your work as accurate as you need it as fast as you can achieve. Be willing to understand the tradeoff and set expectations for your stakeholders accordingly. Be clear that perfect and immediate are mutually exclusive.