With a username like @quant1 its no wonder you've got a rose-tinted view of HFTs. HFTs like to use descriptions similar to yours, to make out they're the great saviour and they are doing everyone a favour. They're not, they're a waste of space and pure noise. I was very pleased to read recently of the substantial decline in HFT revenues, finally getting a taste of their own medicine.
Speaking personally, I don't know, I only place limit orders myself. However, I would fully expect that market orders on IEX would have the benefit of you not being subject to predatory activities by the HFTs, i.e. that you would actually get a fill at a reasonable price instead of some artificial sub-penny rubbish given to you by an HFT when they front-run your order.
I have read most stuff about hft and then makeown research.from my perspective I think quant1 aproximation is quite accurate.the nowdays features you can use to send an order is huge and hft do not change the value of market. I understand IEX and worries at markets but at least for me (maybe I dont usually send much high size orders) hft dont seems to break the trading process.
One other feature that's not being thoroughly discussed here is Reg NMS. No matter what, orders (besides inter market sweeps) will be filled at NBBO. Not to mention, if the market moves then your order is a sitting duck for a whole 350 micros.
@quant1, you sound just like a HFT PR guy ! You are trying to defend the indefensible, there is no need for a "more thorough discussion". As you well know, the HFTs consider Reg NMS an arbitrage opportunity. As for your latter claim about IEX resulting in people executing at stale prices. What rubbish ! Shows how little you know about IEX. The argument you try to make there is just the sort of paltry nonsensical argument your HFT friends make. The arguments you seek to make are exactly those that Citadel, Tabb and other HFT-friendly parties tried when they were trying to prevent IEX becoming an exchange, and all those arguments were thoroughly disproven as nonsense.