ccooper, Currenex does not admit to a "last look" feature - but many traders do. It is difficult to prove that this feature exists than by experience. All these firms police themselves and it is difficult to bust them at their own game. The NFA is cracking down on forex websites and small firms like ours, when they should be going after the banks, FCM's, and institutional platform providers. Police them and you eliminate 90% of the problems in this market.
Lon Eagle, we have tried ODL's Currenex (with Strategy Runner), BGC's Currenex (one experienced scalper that ran tests for us said that something funky is going on in the background - still trying it though), Capital Forex Pro's Currenex (will start using it now), and PFG (now trying their Platinum institutional platform with floating spreads with a particular trader that will be trading an institutional account from an allocator for us). I haven't tried HotSpotFxi because the visual liquidity and spreads look worse than for the above brokers.
If PFG's Platinum platform works well, we might use it for more traders because the Currenex GUI just plain sucks. It's a pain keeping track of the current position P&L in real time and the total P&L.
Since April, Currenex has also eliminated all market order functionality from their platform, which increases trade rejections significantly when the market is moving and doesn't let you place limit orders outside the market with one click.
I don't know if your experience is any different.