I bought one of these 2 weeks ago as I liked the idea of a combined unit and thought it was a competitive price. I had it on test in the garage for 48 hours (actually 24 hours on each setup) and it was fine. I went into Nasa as I was on my way down the A1M anyway, and bought one "over the counter" - I did phone first though.
I spoke to one of the guys at Nasa (an engineer) and he told me that the tricolour had been modified to take care of voltage spikes caused by battery chargers (they thought from a couple of failures), plus something to make it less susceptible to lightening strikes. They also burn in all units I was told.
I'm just finishing a new electric panel so the reverse polarity switch is incorporated into my new panel. Only one small niggle, I wish there was a small bezel to go on the switch to indicate masthead/tricolour - anchorlight.
No connection with company just a happy user of Nasa kit and as someone has already said, they are British and for me that counts.