I've had T1DM since 1966 and hav been pumping since 1983. I've been using the Nav since last year. I wear it continuously. I can't count anymore how many severe lows and highs have been averted by this technology. Of course, A1C is tighter than ever (below 7%). I chose the Nav based on an insider recommendation. It took a while to get comfortable working around the 10 hour cal time, but I know this is short lived with the Nav 1.5 now in Europe. I LOVE the shallow penetration depth of the sensor, compared to the other two out there.