Low spread broker gives more benefit especially when we trade scalping, with lower transaction cost gives better chance to getting quicker target, I also use ECN broker low spread.You can check for reviews and test their services with a demo account. Everyone might have different criteria but personally, I would go for transparency and easiness to use. That is why I look for an ECN broker with a low spread. Mainly because I’m a bit unsure about the non-ECN brokers.