I love my Innovate LM2. I've heard lots of people have problems with them but I have mine for quite a while and never an issue. I log RPM an AFR, and soon will probably be logging IAT and ECT. With any one you choose be sure to free air calibrate it regularly. Any sensor is only as good as it's calibration. Reading plugs is great for a base line but if I would have relied soley on plugs my cast pistons would have been all over the road by now. I'll get flamed for saying this but some of the old heads need to learn to trust alittle more technology now and then. If you watch ebay close you can pick one up in the $250 range. I bought mine for $230 on sale