If you're messing around with single lots of micros - obviously you've got no reason to worry?
By the way - I've had slippage on MES and have experienced times where I'm not instantly filled with limit orders on 5-lots. And this have been on a regular day.
Pretty much never happened on the full ES contract.
https://www.elitetrader.com/et/threads/nq-liquidity.340961/
https://www.elitetrader.com/et/threads/nq-jumping-around-is-it-ib-feed.341401/
It's not my statement, but one that's been repeated by many on this site over the years. I've never done a detailed comparison myself as I've had no interest to do so, but I've taken brief looks and I don't see a huge advantage with the NQ for my trading.
It can move further at times though - in both directions.
I suppose that is correct. I've never tried to trade 50-100 contracts on the NQ, because I do not have enough money for the proper risk management of $500,000 to $1,000,000 to pull that sort of move, in a market when it ranges 200 points per day.