Any performance metric gives information. I begin by asking the following;
1) What is the question I want answered?
2) What performance metric will answer that question?
3) How well does it answer that question?
Unlike many people who assume they should be traders, I do not. I am trading to make money. That takes anywhere from 2,000 to 3,000 hours of my time per year, plus the electricity cost for lighting, air-conditioning and computer. If a simple buy and hold gives me a better return, then I have no business wasting that time and money trading. If I cannot beat a comparable index, I would be better off just buying the index.
I am however realistic about not becoming a great trader overnight. So until I consistently beat the indices and do better than buy and hold, I allocate only a small percentage of my funds to trading. When my metrics tell me I am doing a great job trading, that percentage will increase significantly.
The other performance metrics are interesting of course, and used correctly help to point the way to improved performance.