I’ve found that reviews mentioning withdrawal times and actual support experiences are usually honest. If someone took the time to write about how fast their money came back or how long support took to reply, they probably had real experience.
I also look for reviews that mention downsides along with positives. If someone says “The spreads are tight but customer support was slow to respond,” that feels real to me.
Then I combine that with rebate terms. If two brokers have similar support reviews but one offers better rebates, rebates become the tiebreaker.