I have two of these units in my 450s. I think they are a great but like md said the install can be tedious. After you do a couple of them you learn a few tricks. My second unit failed about an hour after install but was repaired by MDC after I returned it to them.
I hope if somebody like Smart Madness handles these that problems can be handled locally.
The Scan Gauge shows many of the same functions plus trouble codes but only four things at one time and looks add on as opposed to factory. Much cheaper also. I have both units on one car and love them both.
Cheers, Dan