Kyte had Ecco back during summer when I was talking to them. Eventually, I had to go with TT though. But I'm getting my own app (front-end) developed which is more customizable than what TT can do.
As for Ecco, it's a nice suite but surprisingly expensive compared to X-Trader Pro - It really should have been half the price of TT, but it's not. Although I don't know for sure, I think Ecco has fewer gateways (exchanges) than TT and also the Autotrader and Spread Driver extensions for TT have some sweet functionality which I think would require custom programming through Ecco's API to achieve.
One pro for Ecco is that it seems more "nimble" than X-Trader Pro which is the absolutely WORST resource hog I've seen.