My thoughts may come accross as being biased which I do not intend to as I tune cars , but I will give my personal opinion. The software is not as easy to use and datalog as you guys think. There is not a set of instructions that guide you through, although it is not rocket science it will take a little while to get your head around Although a majority of the tuning can be done without a dyno, you will need a dyno to get the last bit of performance from your cars even down low in the rev range. The back up from SCT is pretty ordinary to the point where they don't even answer questions on their forums. Their forums are not a step by step guide to tuning cars either. The software is not layed out in a way that is easy to find a parameter that needs to be adjusted, ie there can be 4-5 tables that may need to be adjusted just to get the air fuel ratio to your desired point. I have done the last 3 Nizpro tuning seminars and keep learning new things all the time. The first time I did the tuning seminar, I had no idea where to even start with using the software and I've been a mechanic for quite a few years. I also thought that I could sucessfully tune a car without a dyno - wrong - I have now invested in a $77000 dyno just so I can tune. The cars do have knock sensors, but they can not be relied on correctly to pick up knock and the sensors themselves require quite a bit of tuning to make them work correctly. Jerry from SCT actually hates knock sensors because of this reason. You will need some form of wide band o2 sensor to check your air fuel ratios. While on about air fuel ratios, timing will need to be different for different A/F so you will need to monitor them closely. I could go on and on, but I'm not great at typing what is actually going on, Maybe Danny could elaborate a bit better than I can. Good luck with tuning if you do get it, but be prepared for a huge learning curve and also a warning that part of that learning curve may end up as damaged engines. There is a lot of satisfaction in doing things yourself. Also don't expect any back up from Capa if you buy the software directly from the states. Good luck and keep us informed how you go :ifiusethisimafag: