I never used a $0 commission brokerage. I paid plenty of fees...in and out. Payment for order flow will almost always screw the little guy because of time. When I was trading I always worked with a direct brokerage where I could actually see the order flow, numbers of buys and sells lining up. All I had to do was click on the current offer/sell and bam my trade was done. I bounced around for a few years with brokerages but finally settled on Tradestation because I loved their charts. I learned how to code my own programs for them.
The brokerage houses who prevented buying gamestock shares all need to be tried and jailed. Clearly market manipulation intended to protect wall street while harming retail investors.