I recently installed a meth injection system in my twin turbo. I did it for the safety of the car under boost as well as the performance increases. I am VERY happy with the results. My car dynoed at 528 RWHP at 9.7 pounds of boost with 92 octane pump gas and the water/meth spraying. Before I had the water/meth injection, my tuner stopped at 440 whp because of hints of detonation. He said the engine was so "happy" with the water/meth that he thought the engine would approach 600 WHP with more boost. I told him that the 528 was enough for me.
I used the high quality parts from FJO Racing. I did a lot of research and although, there are cheaper systems and comnponents, I like the quality and completeness of the FJO system. The plumbing fittings, and filter are stainless steel not brass. They have a good website with photos and info on their system and components. They were VERY helpful in advising me during my research and installation and tuning.
P.S. I have pictures but don't know how to post.