Wideband O2 sensor ("shoulda bought this years ago")

For anyone who has been considering getting one of these but wasn't sure for whatever reason, DO IT. I just got my Innovate LC-2 wideband sensor with digital gauge wired in today and on the first drive with it I found that my Carter AFB has been running no leaner than 13.8:1 at cruise. I bought this kit for $229 and when I think about it I have put 10,000+ miles on this engine since I built it three years ago; the amount of money I have wasted on gas from having a richer-than-needed cruise circuit is probably close to that if not more. The best MPG I have gotten is around 17 on the highway and I currently average around 15 with mixed driving. If I can get the ratio above 15 at least (preferably 16) I should be able to gain 2-4 MPG or more. That's a lot of money over just 5-10k miles.

Also now I can tune my 750 Mighty Demon with ease :evil3:

Does that one log data that can be downloaded? Also, how many O2 sensors does it come with? If only one, which exhaust side do you put it in? Or does it even matter?

I've been thinking about installing a wideband myself, but know nothing about them.