Try studying some $$$$ trading platforms and it seems that rather simple to implement features are missing from MT platform because well, they might tip the balance and retails losers might actually end up break-even (and then there would be the 5% or more of winners). It’s not fun to play video games with people with special/secret tools or just plain better players and same goes here. I don’t believe the bank traders are that much better, they are just better tooled and can pay to get the news sooner/have lower latencies. Then there’s things like “last look” which can be gamed only by the sell side to have very decisive advantage. I didn’t even mention the lack of various ways to execute orders in MT platform.

The question really is, if you are profitable with MT, would you be more profitable with something else? Given everything that’s missing from MT(4) it’s certainly likely.

Slippage could be a very large part of costs and MT(4) doesn’t really give you everything there is available to minimize it.