the are quiet fiddly at the start but once you get the hang of it and set it all up it performs well. Prices have dropped a bit which is nice for those looking at them now but factor in a good amount of time spent to install it properly.
Mine was one of the first of the new versions i think that came out with the serial port in the rear, it had some problems with the sat's in the sth hemisphere and how it was set up so had to be sent back to the UK.
I have the Dash 2 with sensors for Ambient and intake temps, water exit temp, engine oil temp, diff oil temp, oil pressure, TPS, wired up the brake pedal switch as well.
I am running a power fc so are not able to use some of the new functions they have come out with the cables that log everything from the ECU but this can save a heap of hassle.
Accuracy is very good and with the 20hz and going through the right start log procedure i find i have very minimal walking with the gps aerial sitting on the dash of the car.