a demo account is pretty much a must when you first learn about trading so you can practice. Micro/cent account is when you feel confident and have a strategy that you can stick to so you want to switch from demo to live account trading.
I have done a lot of trading on a demo account and now thinking of actually going for live trading on micro. When did you start live trading?
Beginners should try to use a demo account from my personal experience, before going live with micro account. Because you need to understand and explore the market thoroughly.
Trade with a micro if you are ready to take a risk in the market. However, it would be better if new traders start with a demo account as this will help them to build trading skills.
One should always switch to a micro account after analyzing their risk appetite or stick to demo for better understanding.
Demo is good for backtesting but it is unlikely that you will be emotionally prepared to ignore market noise and stick to your trading plan. Sometimes it is hard to do since you want to believe that your strategy works which forces you to accept trading losses, on the other side you also should realize that your strategy may be losing and at some point in time you should revise or switch to something else. That's why it is so difficult to make correct decisions.