I finally managed to pass through MIA at the same time the INSPASS office was open (most of my flights arrive at 4:30 AM, and the office opens at 6:30). I had been carrying my application around for several weeks, so was ready to get it done.

The processing is pretty quick, the whole process takes about 15 minutes, and includes filling out the information on their PC application, digital fingerprints, digital palm prints and digital picture. They then generate the card on the fly, and away you go. By the way, there is no cost, and the card is good for one year. I'll try it out next time I fly to MIA, and then report.