I've been routing limit orders to IEX with IB for weeks now just fine. I believe previous poster was having problems with stop orders specifically, which I don't use.
Does TradeStation now offer orders that reroute if they don't get filled at IEX now? What about LightSpeed?
IEX routed STP orders still are not working at IB. It's been about four months now and countless claims of being "fixed". Incredibly frustrating.
The HFT and dark pool game is way, way in the past!!!! The new game has still not be released to the public. But it is the best one yet. Don't worry, they will make their billions for the next few years, then write books about 2014 in the year 2021 and you can think you are up-to-date on trading technology. Just like nobody could really figure out the game before.....now it's almost impossible.