SC,
I do use the iLap system. It comes down to what was the best system I could deploy and what would work for my visitors. Luckily, the software is the same as for the famous ambRc system. With the lower system cost combined with the lower transponder cost, it made sense in this case. There is a series of tracks in the area that have adopted this approach. The extremeRC, Barnyard, and Strictly are some others I know of. One neat fact that does not matter to me just now is that the transponder is very small, and I heard rumor that a much smaller one is in the works. This would make things like mini-Z's and those other micro cars raceable.