No, I'm not affiliated with OQ, take a look at comments I made about open quant, and then you'll be certain I'm not affiliated with them.
I was concerned about how OQ could steal my code. I knew that right when you signed on to OQ it would connect to their site to "check for updates" I was concerned that they "could be stealing code" they ended up changing the software for me so that I could unclick the check for updates, hence... no connection... no way to steal the code
I've written quite a bit about OQ, anyway the bottom line is that Open Quant is truely a complete ATS. As you dig into the other platforms you'll notice that there just aren't options to do certain things, like in Ninja trader you can't adjust the type of exchange while the in the middle of a strategy. As you begin to create your automated strategy and make it better and better, add this here, and add that there you'll find out real quick that what you want to do is really just isn't supported
...but don't take my word, look at the all the functions in the classes and dig into it and you'll see really how incomplete some of them are... and after you put the hard work into 1) learning the software and 2) coding it, you'll damn the day you chose to go with an incomplete one.
just my 2 cents