A lot of valuable information for developer. What’s went wrong?
You wrote not a review, just anti-advertisement.
W3T works at my production server 10 months without any problem. I’m sure everyone can use it, just have to make it judiciously and with care:
1st, do not install it (as any plugin) to the live/production server without thorough testing at the stage/development copy.
2nd, read documentation, think before apply some option – there are the critical choices, e.g. minify CSS or JavaScript. Ask yourself before make something – do you understand what are you really doing?