Apologies if this was already discussed, but recently I was recommended Sterling trader for hft. 1. What's the API like? 2. Do they have data feed + execution or execution only 3. Do they have simulation environment so I can develop my software there 4. Are they expensive? 5. How they compare to IB 6. Do they have Java api? 7. Do they offer direct market access? 8. Colocation? 9. If you use it for hft, what's the latency like? 10. any other personal experience is also very appreciated here.