EA Studio has been great for me during the last year. There is so much written in here but I want to point out a few things:
1. I spent couple of thousands for ready EAs from the MQL5 market that never worked well. And now I make daily better strategies.
2. The system from Petko that allows me trading with 100s of EAs at the same time is just impossible without the EA Studio
3. Backtesting Forex strategies has never been easier and faster. I love the fact that I am not doing it on MetaTrader any more :)