I have been happy with GSA Captcha breaker since it came out, it was the best solution for accuracy and it is still the best for the functionality of being able to rout different captchas to different solutions. Now that botmasterlabs has dropped XEViL to the public I think it has beaten it for accuracy.
I just wanted to note that I have Website Contact running at 100 threads posting at this moment, with recaptcha service emulation running to XEViL and it is kicking ass!
I have noticed he you run the software in scrape + post mode, it hangs a lot! as of this moment brilliant though it is you can not set and forget, hope this minor bug is addressed.