I do measure slippage, and the night before last again I experienced a 1.5 pips slippage with Darwinex but not with the other broker, which again resulted in a big difference in results. I can show the trades if need be as comparison.
I won't mention the other broker as it's not about knocking Darwinex vs someone else. I guess I fully appreciate that my strategy is very sensitive, and there may well only be a handful of ECN / STP type brokers that offer sufficient liquidity at this time.
I then also traded with a 3rd broker - and it went well until my lot sizes got up to around 8 lots before I started experiencing bad slippage with them also - I subsequently found out that their top of book liquidity was generally around 500,000.
For strategies such as mine - it may be a good idea to have an incubation period on a Darwinex account before allowing it to create a Darwin.
Old broker --> Migrate --> Darwinex (trade for x amount of time) --> compare results pre and post migration = ability to create a DARWIN
Gets complicated I know because other people's strategies don't suffer from this.