I just got my hands on one of these ScanGauges and I gotta say I'm impressed. The quality of the design is top notch and the overall experience using it is up there! I was able to scan my codes in no time and clear them. The digital gauge features really cool too and the rate the date is updated is pretty impressive (I've read this is car specific as to the speed). It says in the manual it came with that I can even program the gauge to read data I want it to pull from the car or calculate and I believe this could potentially include AFR readings as my car has wideband stock.
Haven't used the trip computer yet but I'll give feed back as I do - it is quite in depth with features such as cost per mile, cost per tank, miles to fill up, etc.
Thought I'd give a short hands on review - they sent me the unit with the latest software update which is supposed to add a few things and fix some errors. This is the version I am are now selling as of this week.