I'm about two year in (two weeks shy) and my last check (last month) said 8-9 more years at the rate I'm using it. I was told at installation that five is the average. I think the only time I'm paced any more is when I sleep, just due to my natural sleeping rate being lower than the floor they've set. I'll have to ask.
Used the card about a week after I got it due to my place of employment at the time. Haven't used it at an airport.