I have been a trader using TT as trading system. For quite sometime trying my hand at automated/algo trading.
From Trader's perspective: The look-n-feel, support and stability of TT beats Stellar. However, Stellar is usually the front runner in providing new features. In my opinion TT follows it. Feature-wise I'll rate Stellar better than TT. I think a good networking guy is what is needed for those who complain latency/speed issues. Post 2007, when Stellar made some changes in the way it uses its messaging system, I have not seen many people complaining about it. In fact, as per my knowledge a good bunch of traders (20+) have shifted from TT to Stellar in a very volatile product.
From developer's perspective: Again support, documentation and ease-of-use-wise TT's XTAPI is awesome. But again, Stellar's API is much robust. I think it will be better if they (Stellar) also expose their API in C# .NET to comfort the developers who do not wish to develop in cumbersome C++ environment. Experts will note that this will come at performance cost. I have personally done this. What else will speak about their confidence that Stellar's GUI is built on their API. Whereas TT's XTAPI (in my opinion) was developed 'on request' to support Automated trading. TT do not expose their autospreader and some standard algo strategies through API while Stellar does. The only negative in Stellar API is lack of documentation (except of doxygen generated one) but to my surprise this is countered by lightening fast response during daytime.
I may sound like a pro-Stellar guy but all these are my observations. In my opinion TT has enough money to beat Stellar in all these areas. May be it is not part of their strategy to do it (though in a lot of cases they TT is 'following' Stellar). I should rather say that Stellar is a new age architecture developed in mid-2000's while I think TT's architecture was developed in mid 90's. And therefore the difference in features.
