I forgot to ad the most important point we should all consider, the broker data.
People who have traded futures and stocks for 20+ years would never ever even consider using charts and data provided to them by anyone other than a pure data provider.
Because of course it gets tempting for the broker to fiddle with the data in order to not have to even clear any of your trades and just hold them server side make you lose and keep your deposit.
Data does not come under the NFA CFTC regulation because you sign a disclaimer when you sign up that says although they try and maintain the accuracy of market data and charts etc they cannot be held liable for any mistakes in it.
MT4 is a great platform however it easily exploited by the broker.
Eventually when someone gets some expensive programming done to have a bridge to allow pure E-signal feed into MT4 and the trades cleared through a commission based ecn who couldn't care less how you trade or whether you win or lose because they get paid anyway, like MBtrading, they will find EA's and indicators to be alot more profitable.
The markets are hard enough as it is they always have been since they started, to have to be up against some guy sitting in an office altering your data on the fly to make your system generate false signals early exits late entry's etc is beyond the scope of just beating the markets.
People who dismiss this usually are either new to trading or don't trade and encourage people to trade because they are selling something to do with it and don't care if someone loses money because there next sucker is just around the corner.
Backtesting and Demo trading can be considered completely useless you need a live account and paper trade it.How many times ive heard of someone trade a demo into 3-400% profit then go live only to lose the whole account in 1 week.Its not the same.Demo is designed to make it look profitable and easy if they made demo's the same as live no one would ever open an account.