the brokers that sponsor here would be my first choice. they are all better than tradestation. look at the sponsors
During the US session, when the NQ is not "nervous" and no economic event, slippage should be between 0 (buy at the ask, sell at the bid) and 2 ticks maximum. Unfortunately, when a physical stop is needed, this is because of a sudden change in direction (big orders, big players) that causes a lot of abrupt changes (nervousness), at least for me. Slippage can then be between 2 and 5 ticks. Easy to say, but market orders are not our friends. And I agree with Mark about Tradestation. I really like the look of their charts, but everything else is terrible, with no exception.