I use Tradestation personally.
pros -
- lots & lots of code out there for you to plug into your systems
- it's component based, so whilst it's not really OO, it is structured
- you can write DLLs and plug them into TS - which means it is extensible
- there is a huge community of TS developer out there traders laboratory, TS forums etc
- strategy automation tools, analysis, stock screener, charts, radar screen
- tight data/broker integration
- runs in memory - so it's quick
- interactive debugger
cons
- order management is quite sucky from the language, you don't get all the order types that you have from using it manually
- support take some nudging to help you out
-sharing data between charts/radars/strategies isn't in std product - a free DLL is available
- scripts are executed on ticks, and I feel that you should be able to run code on different events - times, rejections etc. Saying that you can still do all you want once you get your head around the timing cycle
In terms of 1 language vs another language - I'm not sure what you'd need to do that isn't possible in TS.
What I'd like to see is a full comparative analysis between TS, Amibroker, Ninja, Meta Trader etc.
After going through the pain of learning one platform and making it perform, I'd rather not learn another until I know what the supported features are. I have looked around but not found a good comparative analysis though.