One of the other issues that doesn't appear to have been mentioned is that demo accounts always allow you to trade at the prevailing prices whereas in 'real' accounts the brokers do what they can to scupper the trade and give you the worst deal. This means slippage is the order of the day or even non-fills.
Why do you think so many brokers offer free software, free demo accounts and the enticement of 'free' money ? Simply because once they have your money they'll do their damndest (is that a word ?) to stop you getting it back.
Look carfeully before you open an account. Personally I use IB and operate using a great piece of one-click software called Button Trader (just Google it) to get me in and out quickly. I trade news, although not spikes and for me this combination works well.
Have fun.